MLB Player Rankings for the Top 25 Relief Pitchers of 2021 Season
Welcome to Bleacher Report's final positional rankings of the 2021 MLB season!
Throughout the year, we released monthly updates to our position-by-position power rankings, selecting the top 10 players at each spot. Now it's time to finalize those rankings while expanding the list to the 25 best at each position on the diamond, which means every position gets its own article.
Just like the regular-season rankings, players are ranked solely on the 2021 season. Past production and future expectations played no part in deciding the order. This is a rundown of the best and brightest of 2021.
To qualify for inclusion, a pitcher had to pitch at least 50 innings, and he had to have made more relief appearances than starts. That notably excluded Casey Sadler (40.1 IP), Tejay Antone (33.2 IP) and Art Warren (21.0 IP).
Let's wrap up our 2021 MLB Player Rankings series with a look at the top 25 relief pitchers.
Catch up on the 2021 MLB Player Rankings series: Catchers, First Basemen, Second Basemen, Third Basemen, Shortstops, Outfielders, Starting Pitchers
Next 25
1 of 14
With so many good relief pitchers around MLB, it made sense to tack an honorable mention list of 25 guys on to our top 25 list. Here are the players who just missed the cut, listed alphabetically:
- Scott Barlow, KC
- Anthony Bender, MIA
- Brad Boxberger, MIL
- Diego Castillo, TB/SEA
- Aroldis Chapman, NYY
- JT Chargois, SEA/TB
- Adam Cimber, MIA/TOR
- Garrett Crochet, CWS
- Edwin Diaz, NYM
- Tyler Duffey, MIN
- Ian Kennedy, TEX/PHI
- Craig Kimbrel, CHC/CWS
- Michael Kopech, CWS
- Dominic Leone, SF
- Tyler Matzek, ATL
- Collin McHugh, TB
- Alex Reyes, STL
- Richard Rodriguez, PIT/ATL
- Will Smith, ATL
- Gregory Soto, DET
- Ryne Stanek, HOU
- Josh Staumont, KC
- Cole Sulser, BAL
- Ryan Tepera, CHC/CWS
- Lou Trivino, OAK
Nos. 25-21
2 of 14
25. Drew Steckenrider, Seattle Mariners
Steckenrider had a team-high 14 saves for a Seattle bullpen that thrived with a closer-by-committee approach. The former Marlins setup man posted a 2.00 ERA and a 1.02 WHIP in 62 appearances, and he did it while leaning heavily on his mid-90s fastball that he threw more than 65 percent of the time.
24. Jake McGee, San Francisco Giants
After a resurgent season with the Los Angeles Dodgers in 2020, McGee signed a two-year, $5 million contract with the Giants last offseason. The 35-year-old served as the team's closer for most of the season, converting a career-high 31 saves in 36 chances with a 2.72 ERA, 0.91 WHIP and 8.7 strikeouts per nine innings in 62 appearances.
23. Giovanny Gallegos, St. Louis Cardinals
With 14 saves and 24 holds, Gallegos saw plenty of high-leverage action with the Cardinals while making a career-high 73 appearances. The 30-year-old generated a 45.6 percent whiff rate with his wipeout slider, and he finished the season with a 3.02 ERA, 0.88 WHIP and 95 strikeouts in 80.1 innings.
22. Tyler Rogers, San Francisco Giants
One of baseball's last submarine pitchers, Rogers used his quirky delivery to baffle opposing hitters to the tune of a 2.22 ERA and 1.07 WHIP while tallying 13 saves and 30 holds in an NL-high 80 appearances. A late-bloomer in the big leagues, the 30-year-old has club control through the 2025 season.
21. Mark Melancon, San Diego Padres
It seems that as long as he can keep spinning curveballs, Melancon will be an effective late-inning option. The 36-year-old ranks fourth among active pitchers with 244 career saves, and he tacked an NL-leading 39 saves on to that total in 2021. His 2.23 ERA and 1.22 WHIP are not quite as dominant as some others on this list, but he can still slam the door in the ninth as well as anyone.
Nos. 20-16
3 of 14
20. David Bednar, Pittsburgh Pirates
Part of the return package in the deal that sent Joe Musgrove to the San Diego Padres, Bednar emerged as Pittsburgh's best reliever and closer of the future after the Pirates traded Richard Rodriguez to Atlanta. With a 96.7 mph average fastball velocity and a good curveball/splitter pairing, he posted a 2.23 ERA, 0.97 WHIP and 11.4 K/9 with three saves and 13 holds in 61 appearances.
19. Devin Williams, Milwaukee Brewers
After winning NL Rookie of the Year in 2020, Williams continued to befuddle hitters with his signature changeup, throwing the pitch 63.8 percent of the time and limiting the opposition to a .161 average with a 47.2 percent whiff rate. He had a 2.50 ERA, 1.19 WHIP and 14.5 K/9 with 23 holds in 58 appearances.
18. Luke Jackson, Atlanta Braves
While Tyler Matzek and A.J. Minter shined in October, Jackson was Atlanta's primary bridge to closer Will Smith during the regular season, ranking second in the majors with 31 holds. The 30-year-old had a 1.98 ERA, 1.16 WHIP and 9.9 K/9 in 71 appearances.
17. Aaron Loup, New York Mets
Loup had the lowest ERA in baseball among pitchers with at least 50 innings of work, posting a pristine 0.95 ERA over 56.2 frames. He was used more as a middle-inning specialist than a high-leverage reliever, which is why he doesn't rank higher, but he was as effective as anyone in that role.
16. Chad Green, New York Yankees
A workhorse out of the Yankees bullpen once again, Green led all pitchers who pitched exclusively in relief with 83.2 innings of work. The 30-year-old had 10 wins, six saves and 18 holds in 67 appearances, posting a 3.12 ERA, 0.88 WHIP and 10.6 K/9 along the way.
Nos. 15-11
4 of 14
15. Andrew Chafin, Chicago Cubs/Oakland Athletics
Only Ranger Suarez (5.6) and Josh Hader (3.3) had a higher WAR total among left-handed relievers than the 2.9 WAR that Chafin compiled while splitting the season between Chicago and Oakland. The 31-year-old had a 1.83 ERA, 0.93 WHIP and 8.4 K/9 while tallying five saves and 22 holds in 71 appearances.
14. Kenley Jansen, Los Angeles Dodgers
After losing the closer's role during the 2020 postseason, Jansen rebounded nicely in the final season of his five-year, $80 million contract. The 34-year-old reinvented himself a bit, throwing his trademark cutter less and his sinker and slider more. The result was a 2.22 ERA, 1.04 WHIP, 11.2 K/9 and 38 saves in 43 chances over 69 appearances.
13. Raisel Iglesias, Los Angeles Angels
One of only five pitchers with 100 strikeouts as a reliever, Iglesias converted 34 of 39 save chances after joining the Angels in an offseason trade. He had a 2.57 ERA, 0.93 WHIP and 103 strikeouts in 70 innings, and his 13.2 K/9 and 37.7 percent strikeout rate were both career highs.
12. Blake Treinen, Los Angeles Dodgers
Treinen had his trademark sinker working in 2021, leading the majors with 32 holds while handling eighth-inning duties for the Dodgers ahead of closer Kenley Jansen. He recorded a 52.6 percent groundball rate and a 29.7 percent strikeout rate, leaving little room for quality contact. The 33-year-old finished with a 1.99 ERA, 0.98 WHIP and 10.6 K/9 in 72 appearances.
11. Kendall Graveman, Houston Astros
A starter early in his career, Graveman missed most of 2018 and all of 2019 recovering from Tommy John surgery. He returned last year and shifted to a relief role, paving the way for a breakout 2021 campaign. The 30-year-old had a 1.77 ERA, 0.98 WHIP and 9.8 K/9 with 10 saves and 11 holds in 53 appearances, and he could be the most sought-after reliever on the free-agent market this winter.
10. Ryan Pressly, Houston Astros
5 of 14
An All-Star for the second time in 2021, Ryan Pressly was the anchor at the back of the Houston Astros bullpen.
The 32-year-old has converted 38 of 44 save chances over the past two seasons, and he had 26 saves with an 81-to-13 strikeout-to-walk ratio in 64 innings this year, posting a 2.25 ERA and 0.97 WHIP in 64 appearances.
Along with a mid-90s fastball, he also had one of baseball's most overpowering breaking pitches in a low-90s slider. He threw that pitch 342 times in 2021, allowing only three extra-base hits with it and a .159 opponents' batting average.
9. Jordan Romano, Toronto Blue Jays
6 of 14
Jordan Romano hinted in 2020 at the breakout season to come when he posted a 1.23 ERA, 0.89 WHIP and 12.9 K/9 in 15 appearances, and he emerged as one of baseball's most effective closers this year.
After free-agent signing Kirby Yates was lost for the year before the season even began, Romano found himself in the ninth-inning role. He converted 23 of 24 save opportunities with a 2.14 ERA, 1.05 WHIP and 85 strikeouts in 63 innings.
The 28-year-old averaged 97.6 mph with his fastball and backed it with a terrific slider, limiting opposing hitters to a .181 batting average and .576 OPS on the year.
8. Andrew Kittredge, Tampa Bay Rays
7 of 14
Was there a more unlikely All-Star in 2021 than Andrew Kittredge?
A 45th-round pick by the Seattle Mariners in 2008 whom the Tampa Bay Rays acquired in an under-the-radar trade prior to the 2017 season, Kittredge had a 4.93 ERA in 93 big league appearances entering the year.
He wound up filling a variety of roles in an injury-plagued Tampa Bay bullpen, posting a 1.88 ERA, 0.98 WHIP and 9.7 K/9 with nine wins, eight saves and seven holds in 57 appearances while recording more than three outs 24 times.
The 31-year-old pitched primarily off a mid-90s sinker and wipeout slider that generated a 40.8 percent whiff rate.
7. Paul Sewald, Seattle Mariners
8 of 14
Paul Sewald saw sporadic big league action with the New York Mets in the four seasons prior to 2021, posting a forgettable 5.50 ERA and 1.36 WHIP in 147.1 innings.
The 31-year-old signed a minor league deal with the Seattle Mariners last offseason, and after beginning the year in the minors, he was called up to the MLB roster on May 16. He earned the victory with a two-inning relief appearance in his Mariners debut, and quickly pitched his way into a primary setup role.
In a career-high 62 appearances, he went 10-3 with 11 saves and 16 holds, posting a 3.06 ERA, 1.02 WHIP and 104 strikeouts in 64.2 innings. Despite his age, he is still controllable via arbitration through the 2024 season.
6. Garrett Whitlock, Boston Red Sox
9 of 14
One of the most successful Rule 5 selections in history, Garrett Whitlock went from largely overlooked in the New York Yankees farm system to breakout performer in the Boston Red Sox bullpen.
The 25-year-old generated a 49.7 percent groundball rate with his mid-90s sinker, and he backed it with a pair of effective off-speed pitches, using a slider against right-handed hitters and a changeup against left-handed hitters.
The end result was a 1.96 ERA, 1.11 WHIP and 81 strikeouts in 73.1 innings, and he tallied eight wins, two saves and 15 holds while recording more than three outs in 31 of his 46 appearances.
His solid three-pitch repertoire and durability should make for a smooth transition to the starting rotation if the Red Sox decide to go that route, but he is arguably more valuable to them in his current bullpen ace role.
5. Jonathan Loaisiga, New York Yankees
10 of 14
Used as a spot starter over his first three seasons in the majors, Jonathan Loaisiga broke out in 2021 to emerge as the best reliever in the New York Yankees bullpen.
His 3.3 WAR ranked second among all full-time relievers. In 57 appearances, he went 9-4 with five saves and 18 holds while posting a 2.17 ERA, 1.02 WHIP and 69 strikeouts in 70.2 innings.
The 27-year-old ranked among the MLB leaders in average exit velocity allowed (99th percentile), hard-hit rate (99th percentile), and chase rate (99th percentile). After pitching primarily with a four-seam fastball in past seasons, he adopted a more sinker-heavy approach and averaged 98.3 mph with the pitch while complementing it with a plus curveball and changeup.
Loaisiga has three more years of club control remaining, and he will fill a vital role on the Yankees staff again in 2022.
4. Emmanuel Clase, Cleveland Guardians
11 of 14
Armed with an electric cutter that averaged 100.2 mph and a hard slider that averaged 91.9 mph, Emmanuel Clase limited opposing hitters to a .195 average and .481 OPS in 71 appearances.
Along with his 74 strikeouts in 69.2 innings, he also generated a terrific 67.6 percent groundball rate, nailing down 24 saves in 29 chances while posting a 1.29 ERA and 0.96 WHIP at the back of a Cleveland bullpen that moved away from All-Star closer Brad Hand.
The 23-year-old had a 0.82 ERA and 0.61 WHIP after the All-Star break, allowing an earned run only once over his final 32 appearances. Alongside James Karinchak, Clase gives Cleveland a dynamic bullpen duo with multiple years of club control remaining.
3. Liam Hendriks, Chicago White Sox
12 of 14
The Chicago White Sox gave Liam Hendriks a huge three-year, $54 million contract last offseason, and after a rocky first month with the South Siders, he was once again one of baseball's most dominant late-inning relievers.
He closed out the season with 15 straight scoreless appearances, converting nine save chances during that stretch, and he finished the year with an AL-leading 38 saves in 44 opportunities. That gaudy save total was backed by a 2.54 ERA, 0.73 WHIP and a career-high 14.3 K/9 as he piled up 113 strikeouts in 71 innings.
With an upper-90s fastball and a virtually unhittable slider that generated a 57.7 percent whiff rate, Hendriks' stuff stacks up to any reliever in baseball. He is more than deserving of a place among baseball's top relievers in 2021.
2. Ranger Suarez, Philadelphia Phillies
13 of 14
It was difficult to figure out how to slot Ranger Suarez into our positional rankings series.
The left-hander was a dominant presence in the Philadelphia Phillies bullpen over the first four months of the season before moving into the starting rotation at the beginning of August. The splits between the two roles look like this:
- Reliever: 27 G, 1.12 ERA, 0.87 WHIP, 9.4 K/9, 40.1 IP
- Starter: 12 GS, 1.51 ERA, 1.08 WHIP, 8.9 K/9, 65.2 IP
He threw more innings as a starter but made more appearances as a reliever, so we decided to include him with the bullpen guys.
The end result of his unique season was a 1.36 ERA and a staggering 5.6 WAR in 106 innings. It bears watching what sort of impact he can make as a full-time starter in 2022.
1. Josh Hader, Milwaukee Brewers
14 of 14
Josh Hader was once again baseball's most dominant reliever.
The 27-year-old struck out 102 of the 224 batters he faced, posting a 1.23 ERA, 0.84 WHIP and 15.6 K/9 in 60 appearances while nailing down 34 of 35 save chances for the NL Central champion Milwaukee Brewers.
He limited opposing hitters to a .127 average and surrendered only seven extra-base hits while throwing a fastball that averaged 96.4 mph and a wipeout slider that generated a 57.3 percent whiff rate.
The southpaw remains equally effective against right-handed and left-handed hitters. As he continues to move up the arbitration scale, it becomes more and more likely that the small-market Brewers will seriously shop him.
All stats courtesy of Baseball Reference, FanGraphs and Baseball Savant.
