Every MLB Team's Biggest One-Year Wonder Pitcher in Recent History
The one-year wonder is a fascinating phenomenon in professional sports, with the stars aligning for certain players over the course of one glorious season, only for them to fade back into oblivion just as quickly as they emerged.
To be clear, labeling someone as a one-year wonder is not meant to be an insult.
Countless players have come and gone without ever having that one year in the sun, and oftentimes those short-lived standouts endear themselves to their fan base as the years go by and nostalgia kicks in.
Ahead we've highlighted every MLB team's biggest one-year wonder in recent memory, focusing exclusively on pitchers this time around. The position players were highlighted in an article that was published on Sept. 5.
The "recent history" cutoff here was the 2010 season, so each of these one-year standouts turned in their surprise performance sometime in the last 13 years.
Enjoy!
Arizona Diamondbacks: LHP Joe Mantiply
1 of 30
Year: 2022
Stats: 69 G, 22 HLD, 2.85 ERA, 1.08 WHIP, 9.2 K/9, 60.0 IP, 0.9 WAR
Left-hander Joe Mantiply was a 27th-round pick by the Detroit Tigers in 2013, and he had just 10 total appearances in the majors heading into his age-30 season in 2021 when he finally carved out a role in the Arizona Diamondbacks bullpen.
With a 2.21 ERA, 0.96 WHIP and 9.3 K/9 in 39 appearances during the first half of the 2022 season, he earned an unlikely All-Star nod. However, those numbers ultimately proved unsustainable, and he has a 5.40 ERA in 31 appearances this season.
Atlanta Braves: RHP Mike Foltynewicz
2 of 30
Year: 2018
Stats: 31 GS, 13-10, 2.85 ERA, 1.08 WHIP, 68 BB, 202 K, 183.0 IP, 4.2 WAR
A hard-throwing top prospect in the Houston Astros farm system, Mike Foltynewicz was part of the deal to acquire slugging catcher Evan Gattis from the Atlanta Braves prior to the 2015 season.
After posting a 4.85 ERA over 364 innings during his first three seasons in the Atlanta rotation, he broke out in a big way during the 2018 campaign when he finished eighth in NL Cy Young voting and earned an All-Star nod. He struggled next year and was ultimately demoted to the minors, and he had a 5.17 ERA in 259.1 innings for the remainder of his MLB career.
Baltimore Orioles: LHP Brian Matusz
3 of 30
Year: 2010
Stats: 32 GS, 10-12, 4.30 ERA, 1.34 WHIP, 63 BB, 143 K, 175.2 IP, 2.8 WAR
Brian Matusz was the No. 5 prospect in baseball at the start of the 2010 season, behind Jason Heyward (ATL), Stephen Strasburg (WAS), Giancarlo Stanton (MIA) and Jesús Montero (NYY).
He made 32 starts as a staple in the Baltimore rotation that season and finished fifth in AL Rookie of the Year voting, but that proved to be his peak as a starter and he was eventually moved to the bullpen. He had a 3.32 ERA in 186 relief appearances from 2013 through the 2015 season, but he never quite delivered on what once looked like ace potential.
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Boston Red Sox: RHP Brandon Workman
4 of 30
Year: 2019
Stats: 73 G, 10-1, 16 SV, 15 HLD, 1.88 ERA, 1.03 WHIP, 13.1 K/9, 71.2 IP, 3.1 WAR
Brandon Workman spent his first several seasons in the majors as a serviceable middle reliever and spot starter, posting a 4.38 ERA and 1.34 WHIP in 209.2 innings.
Everything clicked in 2019 when he posted a 3.1-WAR season that trailed only Oakland closer Liam Hendriks (3.7) among all relievers that year. The following season he struggled early before he was traded to the Philadelphia Phillies, and he would go on to make just 50 more appearances in the big leagues after his breakout performance.
Chicago Cubs: RHP Justin Grimm
5 of 30
Year: 2015
Stats: 62 G, 15 HLD, 1.99 ERA, 1.15 WHIP, 12.1 K/9, 49.2 IP, 0.6 WAR
Justin Grimm began his MLB career in the Texas Rangers rotation before he was traded to the Chicago Cubs along with Carl Edwards Jr. and two others in the blockbuster deal that sent Matt Garza the other way at the 2013 trade deadline.
The Cubs immediately moved Grimm to the bullpen where his wicked curveball was a major weapon, and he looked like a bullpen star on the rise during the 2015 season. He would log a 5.82 ERA in 158 appearances for the remainder of his big league career, though he did win a ring in 2016 while making six postseason appearances.
Chicago White Sox: RHP Philip Humber
6 of 30
Year: 2011
Stats: 26 GS, 9-9, 3.75 ERA, 1.18 WHIP, 41 BB, 116 K, 163.0 IP, 3.4 WAR
The Rice University starting staff was one of the best in college baseball history in 2004, with Philip Humber (No. 3 to NYM), Jeff Niemann (No. 4 to TB) and Wade Townsend (No. 8 to BAL) all selected inside the top 10 in that year's draft.
The New York Mets traded him to the Minnesota Twins in the Johan Santana blockbuster, and he had a 5.26 ERA in 51.1 innings over his first five seasons in the majors before finally finding MLB success in his age-28 season with the Chicago White Sox who had claimed him off waivers. The next season his ERA skyrocketed to 6.44 and by the end of 2013 his time in the majors was over.
Cincinnati Reds: RHP Alfredo Simon
7 of 30
Year: 2014
Stats: 32 GS, 15-10, 3.44 ERA, 1.21 WHIP, 56 BB, 127 K, 196.1 IP, 2.1 WAR
To his credit, Alfredo Simon had a pair of strong seasons out of the Cincinnati Reds bullpen with a 2.78 ERA over 99 appearances in 2012 and 2013, but he was only a standout starting pitcher for one season.
His stellar 2014 numbers earned him an All-Star selection, and the Reds wisely sold high when they traded him to the Detroit Tigers in exchange for a young Eugenio Suárez. He struggled to a 5.05 ERA in 187.0 innings with the Tigers, had a 9.36 ERA in 58.2 innings back in Cincinnati in 2016, and that was the end of his time in the majors.
Cleveland Guardians: LHP T.J. House
8 of 30![September 5, 2014: Cleveland Indians Starting pitcher T.J. House (58) [7904] delivers a pitch to the plate during the game between the Chicago White Sox and the Cleveland Indians at Progressive Field in Cleveland, OH. Cleveland beat Chicago 2-1 in 10 innings. (Photo by Frank Jansky/Icon Sportswire/Corbis/Icon Sportswire via Getty Images)](https://legacymedia.sportsplatform.io/image/upload/v1694739652/wo2nzk2cw4uw3l0qkuyx.jpg?w=684 "September 5, 2014: Cleveland Indians Starting pitcher T.J. House (58) [7904] delivers a pitch to the plate during the game between the Chicago White Sox and the Cleveland Indians at Progressive Field in Cleveland, OH. Cleveland beat Chicago 2-1 in 10 innings. (Photo by Frank Jansky/Icon Sportswire/Corbis/Icon Sportswire via Getty Images)")
Year: 2014
Stats: 18 GS, 5-3, 3.35 ERA, 1.32 WHIP, 22 BB, 80 K, 102.0 IP, 2.2 WAR
Left-hander T.J. House appeared to be establishing himself as a staple in the Cleveland rotation when he logged a 3.35 ERA and 3.69 FIP in 102 innings as a rookie during the 2014 season.
He was limited to just four starts while battling left shoulder inflammation the following season, and he was never able to reestablish himself. He made six total relief appearances in 2016 and 2017 before his time in the majors was over, with his final outing coming at the age of 27 as a member of the Toronto Blue Jays.
Colorado Rockies: LHP Rex Brothers
9 of 30
Year: 2013
Stats: 72 G, 19 SV, 12 HLD, 1.74 ERA, 1.29 WHIP, 10.2 K/9, 67.1 IP, 3.1 WAR
Rex Brothers had solid seasons in 2011 and 2012 to kick off his MLB career, but he took things to another level during the 2013 season when he supplanted Rafael Betancourt in the closer's role and limited opposing hitters to a .209 average.
He had a 5.59 ERA in 74 appearances the following season and he battled injuries for the remainder of his career, logging a 5.58 ERA and 1.63 WHIP in 179 games during the remainder of his big league action.
Detroit Tigers: LHP Daniel Norris
10 of 30
Year: 2019
Stats: 29 GS, 3-13, 4.49 ERA, 1.33 WHIP, 38 BB, 125 K, 144.1 IP, 3.1 WAR
Daniel Norris was the top prospect in the Toronto Blue Jays farm system and the No. 18 prospect in baseball at the start of the 2015 season, and later that year he was the prospect headliner in the deadline deal to acquire David Price from the Detroit Tigers.
He bounced between the starting rotation and bullpen during his time in Detroit and never quite lived up to lofty expectations, but he was a 3.1-WAR player during the 2019 season, which accounts for the vast majority of the 5.0 WAR he has logged over 10 seasons.
Houston Astros: RHP Lucas Harrell
11 of 30
Year: 2012
Stats: 32 GS, 11-11, 3.76 ERA, 1.36 WHIP, 78 BB, 140 K, 193.2 IP, 3.3 WAR
Bright spots were few and far between on a Houston Astros team that lost 107 games in the early stages of rebuilding during the 2012 season, and the WAR leader on that team was right-hander Lucas Harrell.
The 27-year-old was the best pitcher in a rotation that also featured Wandy Rodríguez, Dallas Keuchel, J.A. Happ, Bud Norris and Jordan Lyles, and his 11 victories accounted for 20 percent of the team's season total. He went 6-17 with a 5.86 ERA and an AL-leading 88 walks the following season and pitched just 65.2 more innings in the majors beyond that disappointing follow up.
Kansas City Royals: RHP Luis Mendoza
12 of 30
Year: 2012
Stats: 25 GS, 8-10, 4.23 ERA, 1.42 WHIP, 59 BB, 104 K, 166.0 IP, 1.9 WAR
Luis Mendoza had an ugly 7.36 ERA in 99 innings across five seasons with the Rangers and Royals before pitching his way into the starting rotation in 2012 and finishing with the lowest ERA of any Royals pitcher who tallied at least 100 innings.
He struggled to a 5.36 ERA in 94 innings the following season before taking his game to Japan where he had a solid four-year run with the Nippon Ham Fighters, and he finished up his pro career in the Mexican League.
Los Angeles Angels: RHP Hansel Robles
13 of 30
Year: 2019
Stats: 71 G, 23 SV, 2.48 ERA, 1.02 WHIP, 9.3 K/9, 72.2 IP, 2.8 WAR
The Los Angeles Angels claimed Hansel Robles off waivers from the New York Mets on June 23, 2018, and at the time he had a 4.07 ERA and one career save in 187 appearances over parts of four seasons.
After some early struggles from veteran closer Cody Allen to begin the 2019 season, Robles ended up pitching his way into the closer's role, and he converted 23 of 27 save opportunities on the year. He followed that up with a 10.26 ERA in 18 games the following season, and while he tallied 14 saves with the Twins and Red Sox in 2021, he never regained his elite form.
Los Angeles Dodgers: RHP Mike Bolsinger
14 of 30
Year: 2015
Stats: 21 GS, 6-6, 3.62 ERA, 1.36 WHIP, 45 BB, 98 K, 109.1 IP, 1.1 WAR
Mike Bolsinger is perhaps best known as the pitcher who filed a lawsuit against the Houston Astros following their sign-stealing scandal. He allowed four earned runs while recording just one out in a start against the Astros on Aug. 4 that season and it ended up being his last appearance in the majors as he was designated for assignment following that outing.
Two years earlier, he actually had a terrific season as a regular member of the Los Angeles Dodgers rotation, but he struggled to a 6.83 ERA in six starts the following year and was traded to the Toronto Blue Jays for journeyman reliever Jesse Chavez.
Miami Marlins: RHP Henderson Alvarez
15 of 30
Year: 2014
Stats: 30 GS, 12-7, 2.65 ERA, 1.24 WHIP, 33 BB, 111 K, 187.0 IP, 4.7 WAR
Henderson Alvarez made his MLB debut with the Toronto Blue Jays as a 21-year-old in 2011, posting a 3.53 ERA in 63.2 innings over 10 starts. Two years later, he was included in the 12-player deal that brought Mark Buehrle, José Reyes and Josh Johnson over from the Miami Marlins.
He showed flashes again in 2013 with a 3.59 ERA in 17 starts, and he threw a no-hitter in his final start of the year. That pales in comparison to his 2014 season, though, as he was an NL All-Star and finished 12th in NL Cy Young voting while compiling 4.7 of his 7.8 career WAR. He underwent shoulder surgery after just four starts in 2015, and he made just three more appearances in the majors once he returned to action.
Milwaukee Brewers: RHP Jim Henderson
16 of 30
Year: 2013
Stats: 61 G, 28 SV, 2.70 ERA, 1.13 WHIP, 11.3 K/9, 60.0 IP, 1.3 WAR
The Milwaukee Brewers were a hot bed of one-year wonder closers during the 2000s, with Dan Kolb (2004) and Derrick Turnbow (2006) each earning All-Star selections before fading into obscurity.
Jim Henderson followed a similarly quick trajectory, debuting as a 29-year-old rookie in 2012 with a 3.52 ERA and 13.2 K/9 in 36 games before taking over as the team's closer the following year. He converted 28 of 32 saves in 2013, but struggled to a 7.15 ERA the following season and closed out his brief MLB career with a one-year stint with the New York Mets in 2016.
Minnesota Twins: LHP Scott Diamond
17 of 30
Year: 2012
Stats: 27 GS, 12-9, 3.54 ERA, 1.24 WHIP, 31 BB, 90 K, 173.0 IP, 2.6 WAR
Scott Diamond was part of a terrific crop of rookie pitchers in the American League during the 2012 season, joining Yu Darvish (TEX), Jarrod Parker (OAK), Wei-Yin Chen (BAL), Tommy Milone (OAK), Lucas Harrell (HOU), Hisashi Iwakuma (SEA) and Matt Moore (TB) as young hurlers who made an immediate impact.
The 25-year-old led the AL with a 1.6 walks per nine innings rate and looked like a solid controllable arm for the future, but instead he struggled to a 5.43 ERA in 24 starts the following year. He would make just one more MLB appearance, throwing one inning for the Toronto Blue Jays in 2016.
New York Mets: RHP Jenrry Mejía
18 of 30
Year: 2014
Stats: 63 G, 28 SV, 3.65 ERA, 1.48 WHIP, 9.4 K/9, 0.2 WAR
Jenrry Mejia was the first player in MLB history to be banned for life due to multiple PED violations, with his third such suspension coming on July 28, 2015. He was reinstated in 2018 but never pitched in the big leagues again.
Prior to that bit of infamy, he spent the 2014 season serving as the Mets closer after failing to develop as hoped in a starting role. He suffered an elbow injury on Opening Day the following season, and he was hit with his first PED suspension a few weeks later. The Mets pivoted to Jeurys Familia in the closer's role in his absence, and seven appearances during the 2015 season account for the remainder of his MLB activity.
New York Yankees: LHP Clay Rapada
19 of 30
Year: 2012
Stats: 70 G, 6 HLD, 2.82 ERA, 1.20 WHIP, 8.9 K/9, 38.1 IP, 0.8 WAR
A true lefty specialist, Clay Rapada made 70 appearances for the New York Yankees during the 2012 season and 115 of the 155 batters he faced were left-handed. He limited lefties to a .186/.263/.255 line with just three extra-base hits, while righties went 10-for-33 with six walks against him.
The side-winding southpaw had a 5.13 ERA in 78 appearances prior to the 2012 season, and he made just four more appearances in the big leagues afterwards, but for one season he was a pivotal piece of the Yankees bullpen.
Oakland Athletics: RHP Guillermo Moscoso
20 of 30
Year: 2011
Stats: 21 GS, 8-10, 3.38 ERA, 1.09 WHIP, 38 BB, 74 K, 128.0 IP, 1.9 WAR
The Oakland Athletics acquired Guillermo Moscoso from the Texas Rangers prior to the 2011 season in exchange for prospect Ryan Kelly. The 27-year-old began the season at Triple-A before he was called up in late May, and he never looked back after throwing six shutout innings against the Los Angeles Angels in his Oakland debut.
The Athletics sold high during the offseason, flipping him to the Colorado Rockies in a deal for outfielder Seth Smith, and he struggled to a 5.74 ERA in 36 appearances over the next two seasons before spending three years in the Japanese League.
Philadelphia Phillies: RHP Jerad Eickhoff
21 of 30
Year: 2016
Stats: 33 GS, 11-14, 3.65 ERA, 1.16 WHIP, 42 BB, 167 K, 197.1 IP, 3.5 WAR
The Phillies acquired Jerad Eickhoff as part of the six-player return package in the deal that sent Cole Hamels to the Texas Rangers at the 2015 trade deadline. He became a full-time member of the starting rotation the following season and looked like he might make the trade a major win for Philadelphia when his 3.5 WAR ranked second only to Odúbel Herrera on the roster.
He posted a 4.71 ERA in 128 innings the following season and pitched just 63.2 innings the remainder of his time in Philadelphia before brief pit stops with the Mets and Pirates to close out his career.
Pittsburgh Pirates: RHP Evan Meek
22 of 30
Year: 2010
Stats: 70 G, 15 HLD, 2.14 ERA, 1.05 WHIP, 7.9 K/9, 2.4 WAR
Asked to name the most obscure All-Star selection of the last 20 years, Evan Meek would be a strong response.
He had decent seasons in 2009 (41 G, 3.45 ERA, 1.34 WHIP) and 2011 (24 G, 3.48 ERA, 1.89 WHIP) sandwiched around the best season of his career. Beyond that, he made just 44 other appearances in the big leagues, and he was a minus-0.7 WAR player outside of his All-Star campaign.
San Diego Padres: RHP Dinelson Lamet
23 of 30
Year: 2020
Stats: 12 GS, 3-1, 2.09 ERA, 0.86 WHIP, 20 BB, 93 K, 69.0 IP, 2.3 WAR
Few pitchers in recent memory have gone from legitimate Cy Young contender to complete non-factor faster than Dinelson Lamet. He teased his swing-and-miss stuff with 244 strikeouts in 187.1 innings during his first two seasons in the majors, but did it with a 4.37 ERA and a fairly high walk rate.
The pieces fell into place during the shortened 2020 season and he finished fourth in NL Cy Young voting in his age-27 season, but injury issues derailed his ascent. The Padres cut their losses and traded him to Milwaukee in the Josh Hader deal last summer, and he has an 11.71 ERA in 27.2 innings with the Rockies and Red Sox this year.
San Francisco Giants: RHP Dereck Rodríguez
24 of 30
Year: 2018
Stats: 19 GS, 6-4, 2.81 ERA, 1.13 WHIP, 36 BB, 89 K, 118.1 IP, 2.7 WAR
Dereck Rodríguez was originally drafted by the Minnesota Twins as an outfielder in the sixth round of the 2011 draft before moving to the mound for the 2014 season, and he became a minor league free agent before reaching the majors in Minnesota.
The Giants signed him to a minor league deal prior to the 2018 season and he ended up being one of baseball's top rookies, but the high-level production didn't last long as he posted a 5.64 ERA in 99 innings the following year. He has made just seven MLB appearances in the years since, including 2.2 scoreless innings of relief with the Atlanta Braves this year.
Seattle Mariners: RHP Carson Smith
25 of 30
Year: 2015
Stats: 70 G, 13 SV, 22 HLD, 2.31 ERA, 1.01 WHIP, 11.8 K/9, 2.4 WAR
The ninth-inning role was in a state of flux for the Seattle Mariners during the 2015 season, with Fernando Rodney, Tom Wilhelmsen and Carson Smith each recording double-digit saves. Smith set a Mariners franchise record with 20 straight scoreless appearances to begin his MLB career.
At 25 years old, he looked poised to be baseball's next elite closer, but with Edwin Diaz waiting in the wings the Mariners sold high and traded him to Boston in a deal for Wade Miley. While he remained effective when healthy, arm issues limited him to 29 total appearances in three seasons with the Red Sox and he made his final MLB appearance at the age of 28.
St. Louis Cardinals: RHP Fernando Salas
26 of 30
Year: 2011
Stats: 68 G, 24 SV, 2.28 ERA, 0.95 WHIP, 9.0 K/9, 2.4 WAR
The closer's role has been a revolving door for the St. Louis Cardinals since Jason Isringhausen saved a franchise record 217 games in seven seasons with the team from 2002-08.
Fernando Salas is one pitcher who took a brief turn in the ninth inning, converting 24 of 30 save opportunities in his first full season in the majors in 2011. His time as the team's closer did not even last season, though, as it was hard-throwing Jason Motte who closed games during the team's World Series run that October.
Tampa Bay Rays: RHP Andrew Kittredge
27 of 30
Year: 2021
Stats: 57 G, 9-3, 8 SV, 7 HLD, 1.88 ERA, 0.98 WHIP, 9.7 K/9, 2.4 WAR
Andrew Kittredge was a 45th-round pick in the 2008 draft by the Seattle Mariners, so the fact that he even reached the big leagues makes him a success story. The Tampa Bay Rays acquired him in a five-player deal prior to the 2017 season, and he posted a 4.93 ERA in 93 appearances during his first four seasons with the team.
That made him easily the most surprising All-Star selection in either league in 2021 when he was one of baseball's best relievers. Unfortunately, his follow-up season was cut short by Tommy John surgery, and he has returned this season with a 5.40 ERA in seven appearances in his age-33 season. There's still time for him to prove he's more than just a one-year wonder, but his age is working against him.
Texas Rangers: RHP Tanner Scheppers
28 of 30
Year: 2013
Stats: 76 G, 27 HLD, 1.88 ERA, 1.07 WHIP, 6.9 K/9, 76.2 IP, 2.2 WAR
Tanner Scheppers served as the primary setup reliever for closer Joe Nathan on a 91-win Texas Rangers team in 2013, and not unlike Neftali Feliz and Alexi Ogando, the Rangers tried to convert him to a starting role after his initial success in the bullpen.
He was actually the team's Opening Day starter in 2014, but elbow inflammation sidelined him after just four starts, and he was slowed by knee issues in 2015 and 2016, effectively derailing his career after a promising start.
Toronto Blue Jays: RHP Steve Delabar
29 of 30
Year: 2013
Stats: 55 G, 6 HLD, 3.22 ERA, 1.35 WHIP, 12.6 K/9, 58.2 IP, 0.7 WAR
The Blue Jays acquired Steve Delabar from the Seattle Mariners at the 2012 deadline in exchange for Eric Thames prior to the slugger's success in the Japanese League.
Delabar spent seven seasons in the minors and some brief time as a substitute teacher before making his MLB debut with the Mariners in 2010, and during the 2013 season his perseverance was rewarded with an All-Star selection. Armed with a mid-90s fastball and a terrific changeup, he tallied 82 strikeouts in 58.2 innings in his peak season.
Washington Nationals: LHP Ross Detwiler
30 of 30
Year: 2012
Stats: 27 GS, 10-8, 3.40 ERA, 1.22 WHIP, 52 BB, 105 K, 164.1 IP, 1.9 WAR
Ross Detwiler carved out a 14-year career as a left-handed swingman who could fill a variety of roles on a pitching staff, but the 2012 season was the only year that he worked more than 100 innings and served as a regular part of a starting rotation.
His performance that year earned him a spot on Team USA in the 2013 World Baseball Classic, and he logged four scoreless innings and a save. An oblique injury landed him on the sidelines during the 2013 season and when he returned he was moved into a relief role, which is where he saw the bulk of his action for the remainder of his career.
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