May Starting Pitching AL Overachievers

 

With most MLB starters reaching 10 or more starts in the 2026 season, the data to work with is becoming more meaningful. There are a few pitchers that stand out as overachievers in May with numbers that are not likely to hold up over time. These four American League starters may be worth avoiding or considering fading in upcoming starting efforts.  

Anthony Kay – Chicago White Sox

The White Sox have been a pleasant surprise this season as a competitive team in the AL Central following three straight seasons with more than 100 losses. Anthony Kay has found success following two full seasons working as a regular starter in Japan. He has a 3.96 ERA on the season, but his FIP is 5.21 as the success for the left-hander could be short-lived. Since allowing eight runs in a late April start in Phoenix, Kay has a 2.87 ERA, but he has modest strikeout results and in his last six starts he has been able to strand nearly 82 percent of his baserunners. His FIP is still 4.38 in his last six starts and in that six-start run Kay has faced only one winning team, while clearing six innings just twice. Kay has significantly worse road splits this season and so far, he has pitched more home innings in his 2026 numbers. Credit Kay and the White Sox for a nice month of May, but Kay isn’t likely to provide above average results the rest of the way. 

Joey Cantillo – Cleveland Guardians

The Cleveland franchise has consistently developed young pitchers with success, but Joey Cantillo was drafted back in 2017 and he will turn 27 this year. He had success for the Guardians last season in a variety of roles in his first full MLB season and the results appear similar at first glance in 2026 for the left-hander. Cantillo had a 10.2 K/9 last season, but that rate is just 8.1 this season. He has also sported a concerning 4.8 BB/9 so far in 2026. His FIP of 4.50 towers over his 3.57 ERA in 12 starts and Cantillo has allowed four or more runs in four of his last eight starts despite mixing in two scoreless outings to post a strong month of May overall. Cantillo has cleared six innings just twice in his 12 starts and his FIP is 5.13 since May 1 with his K/9 crashing to 5.9 to mirror his 5.9 BB/9 in his last six starts. Cantillo is 3-1 in May decisions and the Guardians find ways to win in a lot of ways, but Cantillo should not be a play-on pitcher in the Cleveland rotation. 

Stephen Kolek – Kansas City Royals

The Royals have been a disappointment so far this season but in May Stephen Kolek emerged as a quality option on the mound going 3-0 with a 2.77 ERA. Kolek made 19 starts last season with the Padres and then the Royals, pitching well in five late season outings for Kansas City after being traded. His nice conventional line hides just a 4.9 K/9 however and in his 26 innings he has benefitted from a .187 BABIP, an absurdly low figure that is sure to climb in a larger sample size. Kolek has a FIP of 4.18 which is close to where he finished last season with a much higher ERA. Kolek does have strong command and can continue to be a useful option for the Royals, but the 29-year-old isn’t likely to emerge as an All-Star caliber starter for the 2026 season like his current numbers might suggest. 

Nick Martinez – Tampa Bay Rays

Now 35, Nick Martinez continues to find employment at the MLB level despite a lack of strikeout potential. Martinez pitched well mostly as a reliever in 2022 and 2023 with a favorable home ballpark in San Diego following pitching a few years in Japan. He maintained capable numbers the past two seasons pitching for the Reds but this season he has delivered an incredible 1.51 ERA, entirely as a starter in his first season with the Rays. Tampa Bay posted an amazing month of May, but Martinez has a FIP nearly two runs higher than his ERA and he has a HR/9 that is nearly half of his career average. Martinez is on pace for his worst K/9 since 2017, but he has stranded nearly 93 percent of his baserunners for an incredible run of good fortune. Martinez has allowed just one home run in his last seven starts and in 10 starts this season he is yet to allow more than two runs in a start, despite still allowing nearly a hit per inning pitched. Martinez remains fool’s gold, even with the backing of the Rays organization that makes few mistakes, and he should be considered fade material moving forward as Tampa Bay won’t maintain the recent pace of success.