Casey Mize's unreliability on the mound for Padres continues

San Diego Padres pitcher Casey Mize. USA TODAY Network via Reuters Connect

Casey Mize's unreliability on the mound for Padres continues

By Vanessa Serrao | Last updated Sep 3, 2026 11:35 AM ET

Right-handed starting pitcher Casey Mize has continued to struggle on the mound since joining the San Diego Padres.

Across his first six starts, he has logged a 1-3 record with an elevated 6.67 ERA, 15 strikeouts, 32 hits, a 6.94 FIP, a 1.52 WHIP and has surrendered 20 earned runs. His -0.3 fWAR with San Diego is the worst on the team.

In the Padres' 7-3 defeat against the Cincinnati Reds on Wednesday, Mize was hit hard, allowing four earned runs on five hits across only four innings of work and picked up the loss.

His only victory came in his third start on Aug. 16 where he allowed three hits across six innings in a 5-0 victory over the Cleveland Guardians.

Casey Mize’s first 6 starts as a Padre:

27.0 IP | 20 ER | 9 BB | 15 K
6.67 ERA | 6.94 FIP | 1.52 WHIP

His -0.3 fWAR with San Diego is the worst mark on the active staff. pic.twitter.com/PZvVfYH9lu
— Just Baseball (@JustBB_Media) September 2, 2026

Unpacking what's gone wrong with Casey Mize in San Diego

Following a strong 2.70 ERA with the Detroit Tigers earlier this season, his tenure with the Padres started with a disastrous debut, getting dinged with eight earned runs on nine hits, which was a career-worst start for the 29-year-old.

In addition, his overall performance has been intensified by command issues, as he has also given up 10 home runs and six runs across his first three starts.

Mize has yet to find a consistent rhythm since being traded to the West Coast, and according to analysts, hitters have figured him out easily by attacking him with his slider that he's utilized more since being in a Padres uniform.

From March to June, his slider held an Expected Batting Average (xBA) of only .181. But with the Padres in July and August, it has surged to .344. His Expected Slugging (xSLG) of .361 also rose to .516, and his whiff rate of 25 percent has plummeted to 5.7 percent.

Vanessa Serrao

Serrao is a freelance baseball writer who has covered all MLB teams, with particular expertise on the Toronto Blue Jays. She is a member of the Internet Baseball Writers Association of America.

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