The Most Improved Player on Every MLB Roster
The San Francisco Giants have the best record in baseball for a litany of reasons. Chief among them is how vastly improved the players have been.
Veterans Buster Posey, Brandon Belt and Brandon Crawford are all having remarkable seasons. Kevin Gausman is a candidate for the National League Cy Young Award, and offseason signing Anthony DeSclafani has made a tremendous impact.
Every team and player hopes for progression. Sometimes, as has been the case with the Giants, that progression can be drastic. Let's take a look at the MLB players who are showing exceptional improvement in 2021.
Year-over-year improvement was of some import as we made these selections. However, because of the unprecedented nature of the 2020 season, it was also imperative to take a more holistic approach to our analysis of player progression. We excluded rookies since, well, they don't have much of a base to build on.
Arizona Diamondbacks: UT Josh Rojas
Carson Kelly would likely have gotten the nod, but he fractured his right wrist Saturday, an injury that figures to cost him a good chunk of the season. Ketel Marte is having an excellent season but also showed the extent of his talents in 2019. Instead, we went with Josh Rojas.
The 26-year-old has been a key contributor for the Arizona Diamondbacks amid all their injuries, playing multiple positions and slashing .253/.324/.442 with nine homers and three stolen bases.
Rojas had a mere .624 OPS in 157 plate appearances in 2019 and hit just .180 with a .437 OPS in 70 plate appearances last season. However, those struggles have mattered little as he continues to provide value in a utility role.
Atlanta Braves: 3B Austin Riley
Atlanta Braves third baseman Austin Riley has cooled in June after a red-hot May. Nevertheless, he has been one of the offensive forces keeping Atlanta afloat.
Riley was prone to strikeouts as a rookie in 2019, but he has dropped his swing and whiff rates in each of the past two seasons. The more vigilant approach has contributed to more walks while he still makes quality contact.
The 24-year-old is hitting .276 with 12 homers, 33 RBI and a 125 wRC+. His production has been much-needed because the lineup has ebbed and flowed between offensive explosions and fits of low-scoring performances.
Ronald Acuna Jr. merited a lot of consideration for this spot despite having already been one of the best players in the majors. That said, Riley has made strides, defensive deficiencies notwithstanding.
Baltimore Orioles: CF Cedric Mullins
Cedric Mullins is nothing less than a star. He should be an All-Star starter. The rise has been incredible.
Mullins flashed some potential as a contact-heavy player who could steal bases and play a strong defensive center field in 2020. He has been so much more in 2021.
Maybe the offensive numbers will tail off. The Baltimore Oriole has a .271 xBA and .441 xSLG. Even still, his hard-hit and barrel rates are handily the best of his career. Besides, Mullins already does so many other things at a high level.
Boston Red Sox: RHP Matt Barnes
Boston Red Sox closer Matt Barnes has always had strikeout stuff, but he has never been able to harness his command. Until this year, that is.
Barnes had walked 5.3 and 5.5 opponents per nine innings in 2019 and 2020. This season, though, he has slashed that mark to 2.1. The change hasn't been accompanied by a drop in strikeout rate. Quite the opposite, in fact.
Barnes is striking out a career-high 16.0 batters per nine innings, with 52 punchouts in 29.1 innings. He has a 0.78 WHIP, with a 1.66 xERA probably a better means of evaluation than his 3.07 ERA.
The 31-year-old has more than bounced back from a 2020 in which he had a 4.30 ERA. He ranks third among relievers in fWAR.
Chicago Cubs: RHP Craig Kimbrel
Craig Kimbrel has had a wild ride.
The Chicago Cubs signed Kimbrel in June 2019 after he began the season without a contract. The dominant right-hander was anything but that season, with a 6.53 ERA in 23 appearances.
Kimbrel appeared to figured something out last summer after giving up seven runs in his first 2.2 innings, but he endured a tough spring. Now, he once again ranks among the elite relievers.
The 33-year-old has a 0.61 ERA and career-best 0.65 WHIP. He has converted 20 of 22 save chances and is striking out 15.0 hitters per nine innings.
Kimbrel's ability to command his fastball with velocity has been key, especially given how filthy his knuckle curveball has been. That two-pitch combination has helped him post the second-best fWAR among relievers.
Chicago White Sox: LHP Carlos Rodon
Injuries were threatening to get the better of Chicago White Sox lefty Carlos Rodon, who threw just 42.1 combined innings in the past two seasons.
Instead, Rodon has been one of the most surprising stars of the season.
The 28-year-old headlines a rotation that has arguably been the best in baseball. He has a 1.83 ERA in 12 starts, leading the American League in ERA+ (228), FIP (2.39) and hits per nine innings (5.1).
Rodon has unlocked his strikeout stuff thanks to an uptick in velocity. His four-seamer is averaging 95.8 mph, the highest mark of his career. That velocity and location sets up a wipeout slider that has yielded a .132 xwOBA. His success on the hill has been indicative of the White Sox's top strength this season.
Cincinnati Reds: LHP Wade Miley
Jesse Winker and Nick Castellanos are the Cincinnati Reds' top MVP candidates, but left-hander Wade Miley is the most improved player on the roster.
Consider: Miley fell out of the Houston Astros' playoff rotation in 2019 after posting a whopping 16.68 ERA in five September starts. He signed with the Reds in December 2019 but landed on the injured list three times in the second half of 2020, and he wasn't effective when healthy (5.65 ERA in six games).
If there was any doubt Miley could still be a quality starter in his age-34 season, he has surely erased it by now. The left-hander had a 2.88 ERA and 1.09 WHIP in his first 12 starts before putting together another quality outing on Tuesday. He has been magnificent when it comes to inducing soft contact, ranking in the 98th percentile in average exit velocity and 91st percentile in hard-hit rate.
There is no question Winker and Castellanos have been superb. However, Miley has revitalized his career and been a frontline starter for a team that is trying to stay in the mix in the NL Central.
Cleveland: RF Harold Ramirez
Can Harold Ramirez continue to give a starved Cleveland outfield the production it has long needed?
Ramirez is hitting .273 with six homers and a .797 OPS through his first 141 plate appearances. His performance has been particularly impressive because he played just three games in 2020 after landing on the injured list twice.
The 26-year-old was decent in his MLB debut season in 2019, hitting .276 with a .728 OPS. Yet this version of Ramirez appears well beyond that version. Cleveland claimed him off waivers from the Miami Marlins in February.
Ramirez has a 92.2 mph average exit velocity and 51.3 percent hard-hit rate. Those marks are drastic increases from his last full season in 2019. They might also point to Ramirez's sustaining his offense as the season goes along.
Colorado Rockies: 3B Ryan McMahon
Not a ton has gone right for the Colorado Rockies, but at least Ryan McMahon is giving the club a slugging force in the middle of the order.
McMahon has displayed decent pop in the past, though his swing-and-miss tendencies seemed to get in the way of more consistent power numbers. That's changed this season, as McMahon has slashed his strikeout rate by eight percentage points, while his isolated power is up 49 points.
The 26-year-old has 16 homers and 44 RBI and has also been terrific in clutch situations, posting a .971 OPS with two outs and runners in scoring position.
Even more notably, McMahon gives the Rockies another premium defender alongside Trevor Story. He ranks in the 88th percentile in outs above average.
Detroit Tigers: RHP Michael Fulmer
Michael Fulmer's redemption arc is a wonderful story.
The 2016 American League Rookie of the Year was one of the promising young arms in the game before posting a 4.69 ERA and undergoing Tommy John surgery in 2018. He missed 2019 and struggled upon his return, posting an 8.78 in 10 starts last summer.
Detroit has made Fulmer into a reliever, and he has been all the better for it. The 28-year-old has a 3.55 ERA in 38 innings and has converted six of his seven save chances. He ranks in the 94th percentile in average exit velocity and hard-hit rate and in the 78th percentile in whiff rate.
Fulmer is back to being one of the game's better arms, and he could well be a trade asset come July.
Houston Astros: 1B Yuli Gurriel
Houston Astros first baseman Yuli Gurriel has put together strong offensive seasons in the past, but none have been as good as this one.
Gurriel's walk rate is at a career-high 10.8 percent, while his strikeout rate sits at just 9.7 percent. His determination to work counts has paid dividends, as he is slashing .322/.387/.519 with 10 homers and 50 RBI. Gurriel's 150 wRC+ is also in the top 15.
This has to feel like an incredibly rewarding bounce-back campaign for the 37-year-old. Gurriel hit just .232 with a .658 OPS in 2020 and batted just .114 in the postseason. However, he's once again one of the most dangerous bats in a prolific lineup.
Kansas City Royals: RHP Scott Barlow
Kansas City Royals right-hander Scott Barlow has always been a workhorse in the bullpen. He's finally getting the results to go with that workload.
Barlow threw 70.1 innings in 2019 and led all relievers with 32 appearances in 2020, but he didn't post a sub-4.00 ERA in either season. This time around, however, Barlow has a 2.04 ERA and career-best 2.15 FIP. He has struck out 50 hitters in 35.1 innings and ranks seventh among relievers in fWAR.
The Royals have a strong group of back-end relievers, and Barlow has been arguably the best of the bunch.
Los Angeles Angels: DH/RHP Shohei Ohtani
The Shohei Ohtani preseason hype was indeed warranted.
Ohtani has demanded attention with his two-way excellence. The Los Angeles Angles star leads all players in bWAR and might be the leading candidate for the AL MVP Award.
It has been fantastic to see a healthy Ohtani deal on the mound. He boasts terrific velocity with strikeout stuff as good as any in the game, thanks in part to a filthy splitter. The right-hander has a 2.70 ERA in 10 starts, with 73 strikeouts in 53.1 innings.
Yet his offensive numbers are all the more impressive. Ohtani is tied for the major league lead in homers (23) and leads the majors in extra-base hits (41). He also sits atop the leaderboard in barrels, while his 94.1 mph average exit velocity ranks fifth.
Ohtani ranks second in win probability added and has gone from intriguing two-way talent to a dominating and captivating force every time he steps foot on a diamond.
Los Angeles Dodgers: RHP Jimmy Nelson
This might be a reach since Jimmy Nelson did not pitch in 2020. Still, it's impossible to ignore how electric he has been in his return from injury.
Nelson began his career as a starter and finished ninth in the NL Cy Young Award voting in 2017. His career was derailed by shoulder surgery toward the end of that campaign, as he posted a 6.95 ERA upon his return in 2019 and then missed 2020 with a back issue.
However, Nelson has returned with a vengeance. He made the Los Angeles Dodgers roster out of camp as a reliever and has since been one of the best arms in the bullpen. Nelson has a 1.99 ERA in 22.2 innings, striking out a career-high 14.7 opponents per nine innings and ranking at the top of the sport in xwOBA, xERA, xBA and xSLG.
The 32-year-old is also perhaps the most important bullpen arm for a team that should once again contend for the World Series crown.
Miami Marlins: LHP Trevor Rogers
Miami Marlins left-hander Trevor Rogers had a forgettable debut campaign. His sophomore season has been anything but.
Rogers posted a 6.11 ERA and 1.61 WHIP last summer. He has been leaps and bounds better in 2021, amassing a 1.87 ERA through his first 14 starts and giving up just four homers in 81.2 innings after conceding five long balls in 28 innings last season.
The 23-year-old limits hard contact, ranking in the 85th percentile in xSLG. He also gets plenty of swings and misses, ranking in the 83rd percentile in whiff rate.
Miami might not yet have the young positional core to be competitive, but Rogers' ascension bodes well for the future.
Milwaukee Brewers: RHP Freddy Peralta
Freddy Peralta's selection here is as much about his role change as it is his stuff on the bump.
Peralta was inserted into the Milwaukee Brewers starting rotation to begin his career in 2018, but he later moved to the bullpen. He struggled to adapt initially, posting a 5.29 ERA in 85 innings in 2019. However, Peralta showed signs of being a dominant force last summer, striking out 47 hitters in 29.1 innings.
The Brewers moved Peralta back into the rotation this season, and he has been a gem behind Brandon Woodruff and Corbin Burnes.
The 25-year-old had a 2.28 ERA and 0.87 WHIP in 75 innings before striking out 10 in six scoreless innings on Tuesday. Peralta ranks above the 90th percentile in xSLG, whiff rate and strikeout rate, getting plenty of swings and misses with his fastball and complementing the heat with a wipeout slider and plus changeup.
Woodruff has garnered a lot of headlines, and rightfully so. Yet Peralta is every bit as important to Milwaukee's hopes of winning the NL Central.
Minnesota Twins: 2B Jorge Polanco
Minnesota Twins infielder Jorge Polanco has had success before. He hit .295 with an .841 OPS in 2019.
Polanco's success seemed to run out in 2020, though. He was never quite right after undergoing arthroscopic surgery on his wrist in fall 2019, as his batting average fell to .258 and his slugging percentage dropped to .354.
However, Polanco has shown encouraging signs in 2021. He had a woeful .555 OPS in April but rebounded with an .838 OPS in May and was hitting .307 with an .879 OPS through his first 18 games in June.
Additionally, Polanco's batted ball numbers are better than they have ever been, with a barrel rate of 8.7 percent, an average exit velocity of 89.1 mph and a hard-hit rate of 38.2 percent.
His slash line (.253/.318/.434) might not look terrific, but trends and advanced numbers suggest Polanco is at peak performance levels.
New York Mets: RHP Taijuan Walker
Jacob deGrom is at the apex of his career. We will hardly fault those arguing for his place on this list.
However, deGrom already held the title of best pitcher in baseball. New York Mets right-hander Taijuan Walker was nowhere near that conversation entering the season, but he has been one of the better starters in the game.
The Mets signed Walker to a three-year, $23 million deal this offseason. He has rewarded them with a 2.42 ERA through 13 starts.
Both deGrom and Marcus Stroman have been excellent, but it's unlikely many baseball fans foresaw Walker's becoming elite. He has been all that and then some.
New York Yankees: RHP Jonathan Loaisiga
The New York Yankees have one of the best relievers of this generation doing dominant work in Aroldis Chapman, but they also have a number of unheralded arms giving them quality innings.
Right-hander Jonathan Loaisiga is one of those.
Loaisiga's strikeout rate has declined for the third consecutive season, but it hasn't made him any less effective. The 26-year-old has a 1.63 ERA and 0.96 WHIP. He actually ranks ahead of Chapman in fWAR and is 11th among all relievers.
What's most impressive about Loaisiga's success is how he has translated his power stuff into getting soft contact. He ranks in the 98th percentile in fastball velocity, average exit velocity and barrel rate and leads the bigs in hard-hit rate.
The Bronx Bombers have given Loaisiga a heavy workload in key spots. He has answered the bell with a 7-2 mark in 38.2 innings. The win-loss record is an outdated stat, but it can sometimes inform importance, especially for relievers who take over tie games or protect small leads.
Manager Aaron Boone has felt confident handing Loaisiga the ball, and that confidence has paid off.
Oakland Athletics: LHP Sean Manaea
Oakland Athletics first baseman Matt Olson has been mashing the ball in June, posting a 1.265 OPS with seven homers in his first 18 games. Kudos to Olson for what has been a marvelous season, but left-hander Sean Manaea got the nod.
The A's have had success mostly thanks to surprising pitching performances, with Manaea being the strongest of them all. He has a 3.01 ERA in 15 starts, with a 3.07 FIP to boot.
Remember, Manaea missed nearly all of 2019 after undergoing shoulder surgery in 2018. He has since built his average fastball velocity back up, which can only mean good things for the effectiveness of his changeup and curveball.
Philadelphia Phillies: RHP Zack Wheeler
Zack Wheeler finished 12th in NL Cy Young Award voting in 2020. The Philadelphia Phillies right-hander is also so much better than he was last summer.
The most noticeable difference has been Wheeler's ability to miss bats. The 31-year-old struck out just 6.7 opponents per nine innings in 2020. He is striking out 11.0 per nine in 2021, with his whiff rate at a career-high 28 percent.
Wheeler's stuff and command make him a nightmare to deal with, and he also induces tons of soft contact. He ranks above the 90th percentile in average exit velocity and hard-hit rate.
Wheeler has a 2.15 ERA and leads the NL with 96.1 innings pitched. There's not a whole lot opposing hitters can do when Wheeler dots the outer edge at 97 mph and follows with a 91 mph slider or changes speeds even more with his curveball.
Pittsburgh Pirates: CF Bryan Reynolds
Bryan Reynolds finished fourth in the NL Rookie of the Year Award voting in 2019 after hitting .314 with an .880 OPS, only to hit just .189 the following summer.
Was Reynolds' sensational rookie campaign just an aberration? Well, apparently not.
The Pittsburgh Pirates center fielder has quietly been one of the best players in baseball this season, slashing .299/.394/.529 with 12 homers and a 154 OPS+. He ranks 16th in fWAR and 12th in wRC+. That's pretty good, no?
Just for good measure, Reynolds ranks in the 80th percentile or better in sprint speed and outs above average. He is showing five-tool potential.
Pirates fans might not have a whole lot to be jazzed about, but Reynolds deserves more acclaim.
San Diego Padres: RHP Joe Musgrove
Joe Musgrove was regarded as a popular trade target this offseason, and now baseball fans have seen why.
The former Pittsburgh Pirates right-hander has thrived with the San Diego Padres, posting a 2.28 ERA and 0.85 WHIP in 79 innings and striking out 98 opponents against just 17 walks. Musgrove's excellence has been necessary especially with Blake Snell struggling.
We have to talk about his slider, which has been elite. That offering has been the ninth-best pitch in baseball in terms of run value and is the second-best slider, behind only Clayton Kershaw's. It plays extremely well off a fastball that ranks in the 95th percentile in spin rate.
Interestingly, a lot of the advanced numbers suggest Musgrove was even more effective last season. Then again, he pitched only 39.2 innings. The question was whether he would live up to the price the Padres paid for him. There has been little doubt he has.
San Francisco Giants: RHP Kevin Gausman
The San Francisco Giants have a handful of players who have improved in 2021. None have been quite as transformative as Kevin Gausman.
The 30-year-old bet on himself by taking a qualifying offer this offseason after a strong 2020. What a decision that has been. Gausman has been one of the very best pitchers in the game, posting an 8-1 mark with a 1.51 ERA and 0.77 WHIP.
It is a beautiful thing to watch the right-hander pitch. He can spot his fastball on the edges or above the hands and gets hitters to dive at a splitter. In fact, those two pitches rank fourth and third in terms of run value.
Gausman is one of many candidates for the NL Cy Young Award, and his career year has helped propel the Giants to first place in the NL West.
Seattle Mariners: RHP Kendall Graveman
Seattle Mariners right-hander Kendall Graveman was struggling to hang on to his MLB career last season.
Graveman had a 7.60 ERA in seven starts with the Oakland Athletics in 2018. Then he missed 2019 because of Tommy John surgery. He came to Seattle in November 2019, but the results (5.79 ERA) weren't inspiring. Still, the M's agreed to terms on a one-year deal with the veteran, who has been a terrific asset in the bullpen.
The 30-year-old has a 1.31 ERA and 0.68 WHIP in 20.2 innings. Graveman had been Seattle's setup man early, but he got opportunities to close before going on the COVID-19 list in May.
Graveman has struggled since, giving up a run in three of his four outings and suffering his first blown save over the weekend. However, he picked up the save Tuesday night, and there's no arguing the totality of his turnaround has been impressive.
St. Louis Cardinals: LF Tyler O'Neill
St. Louis Cardinals left fielder Tyler O'Neill looks like he was chiseled out of marble. He's practically playing like an ancient Greek hero for the Redbirds.
This is far and away O'Neill's most impressive season. He is slashing .276/.321/.591 with 15 homers and a 154 OPS+. He ranks above the 90th percentile in hard-hit rate, xwOBA and average exit velocity while ranking in the 99th percentile in barrel rate. He ranks second in the majors in xSLG.
It's not just the bat with O'Neill. He won a Gold Glove Award last season and ranks in the 80th percentile in outs above average. The 26-year-old is also one of the fastest players in the majors, ranking in the 99th percentile in sprint speed.
O'Neill looks to be powering his way to an All-Star appearance. Can he also power the Cardinals to the top of the NL Central? That remains to be seen, though he's certainly trying to carry the team on his broad shoulders.
Tampa Bay Rays: 3B Joey Wendle
Who would have guessed Joey Wendle would be the Tampa Bay Rays' most valuable position player?
Wendle has been valuable before. He finished fourth in AL Rookie of the Year Award voting in 2018 and had a .777 OPS last season. Those campaigns still pale in comparison to what Wendle is doing in 2021.
The 31-year-old is hitting .292 with an .841 OPS and 140 OPS+. The latter figure is the highest mark of his career. Many of the expected statistics frown on Wendle's offensive success, but his barrel rate (6.0 percent) is by far the highest it's been.
Plus, Wendle is all the more exceptional on the defensive end. He has mostly played the hot corner for the Rays, though he's also played short. Wendle ranks in the 93rd percentile in outs above average and has amassed three defensive runs saved at both third and short.
Texas Rangers: RHP Kyle Gibson
Texas Rangers righty Kyle Gibson was one of the worst pitchers in the majors in 2019 and 2020.
Gibson had the fourth-worst fWAR in that span and also posted a 5.03 ERA. He has flipped the script in 2021.
The 33-year-old has a 2.17 ERA in 14 starts. What Gibson has lacked in swing-and-miss stuff, he has made up for with craftiness. He mixes multiple pitches and challenges both left- and right-handed hitters with his cutter. Gibson's slider has also been a tremendous weapon this season.
Texas has other trade assets to dangle this summer, including Ian Kennedy and possibly Joey Gallo. Gibson (under contract through 2022) could be every bit as valuable to a team in a pennant race and in need of a starter.
Toronto Blue Jays: 1B Vladimir Guerrero Jr.
Remember the previous statement about Shohei Ohtani's possible standing as the leading candidate for the AL MVP Award? Vladimir Guerrero Jr. might have something to say about that.
The Toronto Blue Jays first baseman has finally realized the superstar hype that preceded him. He is tied with Ohtani for the MLB lead in homers (23) and also leads the bigs in RBI (59), on-base percentage (.440), OPS (1.111), OPS+ (202) and total bases (169).
His batted ball numbers have always suggested he was on the cusp of breaking out. However, significant rises in barrel percentage and walk rate—plus launch angle—have resulted in his going from a promising young talent to arguably the AL MVP at just 22 years old.
Marcus Semien and Robbie Ray have made tremendous year-over-year gains, but it's too hard to deny Guerrero.
Washington Nationals: RHP Erick Fedde
The Washington Nationals have battled back into a decent spot in the NL East, in part because of unsung contributors such as Erick Fedde.
The 28-year-old has been a stabilizer in an otherwise shaky starting rotation, posting a 3.33 ERA and 1.15 WHIP in 10 starts. He has been especially good in his two June starts, tossing 12 scoreless innings and limiting opponents to just six hits.
Fedde's recent surge has been necessary for the Nats since Max Scherzer was on the IL and Stephen Strasburg has been sidelined with a strained neck. His lack of power stuff and his shaky command might lead to regression, but he will be an imperative piece as Washington tries to get back into the playoff mix.