Boston Red Sox Pitchers of the Month - May 2025

The month of May was a difficult one for the Red Sox and the pitching staff as a whole. Underperformance and injuries to some key players left the rotation thin, forcing them to lean heavily on a bullpen that is already showing signs of cracking. Even with the poor showing, there were some standout performances that will hopefully help the Sox regain some stability in time for the offense to wake up again in the summer heat. Here are your Red Sox pitchers of the month for May.

Honorable Mention

Aroldis Chapman 1-1 2.31 ERA (14 K in 11.2 IP) 1.03 WHIP .186 BAA

The flame-throwing closer has continued his turn back the clock season, putting up a solid month of May. Chapman posted a 2.31 ERA and converted four of his five save opportunities. The 37-year-old still ranks among the very best with his 98^th percentile average fastball velocity of 99.1 MPH, and he strikes out exactly 1/3 of the batters he faces (94^th percentile). I don’t think anyone expected him to be quite this good at this age, but his presence at the back-end of the bullpen gives the Red Sox the shutdown closer they have been missing since Craig Kimbrel departed.

#3: Justin Wilson 2-0, 0.87 ERA, (15 K in 10.1 IP) 1.16 WHIP

Wilson wasn’t a high-profile acquisition in the offseason, a grizzled veteran coming off a rough 2024 campaign (5.59 ERA), but his underlying metrics looked good, and the bullpen needed some more swing and miss stuff. That gamble seems to be paying off so far, as the 37-year-old Wilson has been the most consistent member of the bullpen to date. Across 13 appearances in May, he recorded a 0.87 ERA. While the walks are a little high still, Wilson has been getting the job done by limiting hard contact. He ranks in the 97^th percentile in average exit velocity, and his 54.2% groundball rate ranks in the 90^th percentile. 

#2: Brennan Bernardino 1-1 0.71 ERA (10 K in 12.1 IP) 0.95 WHIP

The trend of left-handed pitchers performing well in May continues, although you can probably file this one under “doing better than you realized.” Over 16 appearances in May, Bernardino posted a 0.71 ERA. That was second only to Wilson, while his 16 appearances led the team. Bernardino has suffered from command issues in the past, but when his stuff is on, it gives the Red Sox bullpen another dangerous weapon in the late innings.

#1: Garrett Crochet 2.03 ERA, (39 K in 31.0 IP) 1.10 WHIP

Crochet has been every bit the ace that the Red Sox hoped they were getting when the dealt away a hefty package of prospects. The contract extension looks worth it, too, as the big lefty is leading the majors in strikeouts and innings with 101 over 82 innings pitched. His season ERA of 1.98 is seventh in MLB among qualified starters. He has also tallied 2.7 WAR.

Over his five May starts, Crochet only recorded one win, a 10-1 drubbing of the Royals, and the overall picture of the season would be looking a lot better if the team could find a way to generate some offense when he is on the mound. Outside of that ten-run outburst, Crochet received only nine runs of support over his other four starts (2.25 runs per game). The team is getting everything it asked for from their ace, they just need to get him some wins to show for it.