Boston Red Sox Pitchers of the Month: May 2026

Pitching for the Boston Red Sox was a mixed bag during the month of May. There were some clear highlights, but for the most part, one of the preseason strengths for this club suffered from inconsistent performances. The pitching staff was bitten by the injury bug during the month of May as well, and that has led to there being more questions than answers outside of the names featured below. There’s room for improvement in both the starting rotation and the bullpen from most arms, but with the summer quickly approaching, we are squarely in ‘put up or shut up’ territory; the pitching staff needs to take a big step forward to help keep the team afloat just outside of the playoff picture.

Ranking Red Sox's Best Pitchers in May

Honorable mentions: (Bulk reliever) Brayan Bello, Connelly Early

#3: Sonny Gray

May Stats: 27 IP, 2.00 ERA, 2.71 FIP, 26.2 K%, 8.4 BB%, 1.11 WHIP, 0.8 fWAR

Gray has been utterly dominant since he returned from the hamstring injury he suffered on Marathon Monday in April. Throughout the month, he made five starts and notched four wins. He had one rough start that can likely be attributed to the weather (he was throwing in the pouring rain for that start) but even he would say that’s just an excuse and he needed to be better in the moment. During May, he pitched to more than one strikeout per nine innings and kept his walk rate down to three per nine. He’s been incredible at limiting contact but when people have gotten on, he left them on base at the end of each inning at an 85% clip. He’s getting a ton of whiffs now and that is the game that Gray built his career off of.

#2: Aroldis Chapman

May Stats: 10 IP, 0.00 ERA, 1.28 FIP, 38.5 K%, 10.3 BB%, 0.80 WHIP, 0.6 fWAR

Chapman occupies a space in the second-best closer in baseball conversation behind Mason Miller, so it may be surprising to see him clock in at number two on this list, but this dominance has come to be expected. Chapman has been better than advertised for the Red Sox for the past two seasons, and his ability to still get massive strikeouts while throwing 100+ mph is just an unfair advantage in the ninth inning. It’s gotten to the point where you just assume no one is scoring when Chapman comes in. While he hasn’t been infallible this season — his walk rate is up and he is allowing a bit more contact than last year —  he’s been dominant. The team has kind of forced Chad Tracy’s hand in using Chapman awkwardly, because they tend to go long stretches without requiring a save situation. When he gets the end of the game, even in situations like he was in against the Guardians to end the month, he shoves. For as long as Chapman is in Boston, he’s going to be an imposing presence at the back end of the bullpen.

#1: Payton Tolle

May Stats: 30.2 IP, 2.35 ERA, 2.59 FIP, 26.1 K%, 5.0 BB%, 0.85 WHIP, 1.0 fWAR

The rookie southpaw commands the top spot on this month’s top pitchers because he has been an absolute animal since he was called up to the big leagues. He has only posted two wins over five starts during May, but that’s not due to him being ineffective, it’s due to the defensive lapses behind him and the offense being unable to plate runs with runners in scoring position. Tolle has been striking out more than one batter per nine and walking just under two batters per nine. His fastball mix has been highly touted throughout the start of the season, and it’s proven to be effective during multiple turns through the lineup. He’s working on a curveball that, when he figures it out fully, will likely put him in the ‘ace’ discussion as he builds a résumé worthy of All-Star credentials. His performances in May have been some of the best in the league, and it’s safe to assume that Payton Tolle is going to keep climbing the ladder and step even further into the spotlight with the Red Sox.