Over 200 players made their major league debuts this season. A few will go on to enjoy success over long careers, but most will have careers memorable only for their friends and family members. Following are some notable career debuts, some never before seen in the major leagues.
For this tour of debut seasons among the 30 major league clubs, I’ll be making reference to rankings of 2021 players compared to similar seasons by players of the past. To avoid repeating myself ad nauseum, I won’t state “among debut seasons since 1901”, but that will be my meaning unless stated otherwise. I’m choosing debut seasons rather than rookie seasons because Dr. Doom has posts teed up for year-end awards, including RoY, so I’ll leave the rookie field to him.
Compared to recent seasons, this was not a great year for debut performances. Neverthless, I’ve tried to highlight players for each club who made noteworthy positive contributions but, where that proved difficult, I’ve also identified results that were noteworthy for the wrong reasons, or were just unusually quirky. If I’ve missed players (as I’m sure I must have) from teams that you follow, I offer my apologies and ask that you please give a shout out in the comments.
Let’s start with Reds’ second baseman Jonathan India. India led the debut class with 3.9 WAR and his 21 HR were the most for a Red infielder, and tied for the most by any Red not named Frank Robinson. And, India’s 23 HBP are the most ever in a debut season, surpassing the previous mark of 22 set by Giant shortstop Charlie Babb way back in 1903.
Right behind India in WAR was Ray shortstop Wander Franco who turned heads with a run of 43 consecutive games reaching base, tying Frank Robinson’s record for players aged 20 and younger, a feat more impressive for being interrupted by a two-week stint on the IL. Quiz: what do the games, in which Robinson’s and Franco’s streaks were stopped, have in common?
Another infielder, Tiger shortstop Zack Short (who really is short by today’s standards, at only 5’10”) didn’t fare as well; his .141 BA in 150+ AB is the lowest by a shortstop since Doc Lavan in 1913.
Astro outfielder Jose Siri, a suddenly rare September callup, had only 49 PA, but made the most of his brief time in Houston, slugging .600 with 4 HR, and adding 3 stolen bases; no previous player had matched those totals in a season of fewer than 115 PA. Teammate and fellow outfielder Jake Meyers had a bit more playing time and posted a respectable .761 OPS in 49 games. But, pinch-hitting was not Meyers’ forte, whiffing in all 6 attempts, the most of any player failing to put the ball in play in that role.
White Sox utility man Romy Gonzalez had even less playing time than Siri, but managed to pinch-hit and DH, and play every field position except C, 1B and CF, all in only 10 games. That’s the fewest games for any player with a season playing all of those positions, and all of those positions excluding DH. Quiz: which player had a debut season including games as PH and DH and at every field position except catcher?
Phillies’ utility man Matt Vierling got a hit in first major league PA and didn’t see his batting average drop below .300 at any point the rest of the season. That was partly thanks to a .420 BABIP, making the top 25 highest marks in a season with 20+ hits. Among notables ahead of him on that list are Mel Ott (.451 in 1926) and Stan Musial (.422 in 1941).
Mariner outfielder Jarred Kelenic was drafted sixth overall in 2018 and got into 93 games for Seattle, who will be looking for better results from the 22 year-old than this season’s .181 BA (second lowest in a 350 PA season) and -1.7 WAR (ninth lowest by an outfielder, and second lowest this century at any position).
Cardinal outfielder Lars Nootbar continued a recent trend of St. Louis players reaching 15 R and 15 RBI in brief debut appearances. He’s the fourth Redbird with those totals in seasons of fewer than 150 PA, all of them since 2008. Quiz: which of those players later claimed a league HR title?
Nationals’ catcher Riley Adams was acquired in a trade deadline deal from Toronto and showed some pop and plate discipline with .422 OBP and .465 SLG in 35 games in the senior circuit. Adams’ Aug 17th home run against the visiting Blue Jays made him the first player with a debut season homer against the team he debuted with.
Turning now to the pitchers, let’s start with debut season WAR leader Garrett Whitlock of the Red Sox, whose mark of 2.9 WAR is second highest in a season of fewer than 50 games and 90 IP, behind Ken Tatum in 1969.
Leading starting pitchers (pitchers with starts in 60% of appearances) and close behind Whitlock is Blue Jay Alek Manoah with 2.8 WAR after a late May callup. Manoah’s 6.2 H/9 is third lowest in a season of 20+ starts; it’s an impressive list with Jose Fernandez, Hideo Nomo, Herb Score and Kerry Wood rounding out the top 5.
Tampa Bay’s Shane McClanahan made his big league debut in last year’s post-season, and led this year’s regular season debut class in Starts, IP and Wins, and was second in ERA to Manoah. McClanahan’s season was the fourth of 20+ starts and 10+ SO/9, and with ERA and FIP both under 3.5. Teammate Shane Baz started and won his debut game, becoming the first pitcher to do so when allowing multiple home runs and no other hits. Quiz: which pitcher was the first to record a season like McClanahan’s?
Right behind McClanahan in IP and Starts was Mariner Logan Gilbert who led the debut class in Pitches and Strikes thrown. Gilbert was better than his 89 ERA+ would indicate; that is the lowest starter ERA+ in more than 100 years with WHIP under 1.2 in 100+ IP. Quiz: which pitcher has the highest ERA+ in such a season?
The Twins’ Bailey Ober also made 20 starts and posted a 5.05 SO/BB that is the fourth highest mark in such a season. But, his 92.1 IP is the lowest total, and his 1.95 HR/9 the third highest mark, in such a season. Ober also allowed as many HR as BB, only the third time that’s happened in a 20+ start season, a mark he shares with notable Zack Greinke.
Also struggling with the long ball was the Mets’ Tylor Megill with 1.91 HR/9 that is the sixth highest mark by an NL pitcher in 15+ starts. Megill became the first Met since Nolan Ryan with a pair of scoreless starts of 6+ IP among the first 6 appearances of a career.
Right behind Megill with 1.90 HR/9 is Ryan Weathers of the Padres. His 94.2 IP is the lowest total in any season with 30+ appearances, including 15+ starts and 10+ relief outings. Quiz: which pitcher has the most IP in such a season?
Luis Gil of the Yankees made 6 starts and struck out 11.7 batters per 9 innings. He also walked 14.7% of the batters he faced, though he won’t mind the company he’s keeping; Bob Feller‘s 16.9% in 1936 is the only higher walk rate in a 5+ start season with 10+ SO/9.
Also struggling with control was the Braves’ Kyle Muller who uncorked wild pitches at a rate of 2.2 per 9 innings. Muller made the most starts (8) and recorded the highest ERA+ (107) of 20 starting pitchers with as high a wild pitch rate in a season with more than one start.
The Pirates’ Max Kranick was removed from his career debut after 5 no-hit innings, despite having thrown only 50 pitches. He’s the third pitcher to be removed from a 5+ IP no-hit bid in his debut game, but the first to record a win in that contest (though the Giants’ Red Ames went the distance for the win in a rain or darkness-shortened game in 1903, allowing no hits over 5 IP).
The Diamondbacks’ Tyler Gilbert completed his no-hit bid to record the 7th no-hitter of 2021, tied with 2015 for the most in a season. Gilbert becomes just the second pitcher with a no-hitter in his first career start, after Bobo Holloman in 1953. Quiz: which pitcher had a debut game no-hit bid broken up with two out in the 9th?
Switching now to the relievers (pitchers relieving in 80% of games), Nick Sandlin of the Indians made 34 appearances and posted ERA and FIP both under 3. He also struck out twice as many batters as hits allowed, only the 10th time (all since 1995) a pitcher has done all three in over 30+ IP.
Also posting low hit and high strikeout totals was the Giants’ Camilo Doval with H/9 under 6 and SO/BB over 3.5, the 14th such season (and second by a Giant, after Sergio Romo in 2008) of 25+ games, again all since 1995. Quiz: who was the pioneering pitcher who was first to post seasons like Doval’s and Sandlin’s?
Allowing even fewer hits was the Rangers’ Joe Barlow, whose 3.7 H/9 was just the second mark under 4 in 30+ games, after Kevin Siegrist and his 832 ERA+ (not a typo) in 2013.
Not as lucky in the hits department was the Marlins’ Anthony Bender, who posted WHIP under 1.1 and H/9 under 7 despite a .275 BABIP that is second highest in that group (after Dick Radatz‘s .285 in 1962).
Also posting WHIP under 1.1 were Dodger Justin Bruihl and Rockie Jordan Sheffield, both despite low SO/BB ratios under 2. Those are the first such seasons of 20+ games since 2009.
Though he pitched only 20.1 innings, the Angels’ Austin Warren was money in the bank with a 3-0 record and nary a home run allowed. It is just the 9th season of 15+ appearances by a reliever posting a clean sheet for losses and home runs combined with 250 ERA+ and FIP under 2.5, a group including notables Craig Kimbrel and Kenley Jansen.
Stratospheric ERA+ scores like Warren’s are hard to find, especially in Colorado, where Lucas Gilbreath‘s 140+ ERA+ in 40+ IP was just the fourth such season by a Rockie reliever.
The Brewers’ Jake Cousins recorded 17 straight scoreless appearances to start his career, tied for the 8th longest streak of relief outings, and a 159 ERA+ in 30 appearances overall. That is the 7th highest ERA+ in a season of 30+ games, when allowing more walks than hits.
Control was not a problem for the Orioles’ Tyler Wells whose 57 IP was the second highest total in a season with a 5+ SO/BB ratio when pitching exclusively in relief.
Another workhorse reliever was the Royals’ Jake Brentz whose 72 appearances are 4th most by a reliever posting a 25% K rate. Quiz: which pitcher has the most appearances in such a season?
Not a workhorse at all was the A’s Domingo Acevedo, who logged only 11 IP in 10 appearances, allowing four runs, all of them scoring on home runs. Debut seasons of 10+ appearances only allowing runs via the home run cannot be common, but they are difficult to search for. A couple of other examples are Oriole Donnie Hart in 2016, allowing only a lone solo HR in 18.1 IP over 20 appearances, and Boston’s Austin Maddox in 2017, again allowing only a lone solo HR, this time in 17.1 IP over 13 appearances.
The Cubs’ Keegan Thompson was used mainly in relief for most of the season before making starts in his last 5 appearances. Thompson fared much better as a reliever, with a 2.43 ERA in that role compared to a 5.51 mark as a starter. You have to go back to Johnny Klippstein in 1950 to find another Cub with reliever ERA under 3 and starter ERA over 5, in a season of 5+ starts and 20+ relief appearances.
That’s all for me. So, which first year players caught your eye?
