Report: Brian Kaplan will not return as Diamondbacks’ pitching coach

The Arizona Diamondbacks have parted ways with pitching coach Brian Kaplan, according to MLB.com’s Steve Gilbert.

Kaplan joined the D-backs ahead of the 2025 season after serving three seasons as the assistant pitching coach for the Philadelphia Phillies. His contract expired after this season, and Arizona opted not to bring him back.

During Kaplan’s tenure, the Diamondbacks pitched to a 4.34 ERA in 2,886 innings — 22nd in MLB during that span, according to FanGraphs.

Arizona’s pitching under Kaplan had its ups and downs: Franchise mainstays Merrill Kelly and Zac Gallen showed significant decline, while Eduardo Rodriguez had a resurgent 2026 season after a rough start to his stint with the D-backs.

Improvement from the pitching staff was most visibly seen in the bullpen, where Arizona’s relievers were among the worst in 2025 (29th in win probability added), but among the best in 2026 (fourth in win probability added).

Kaplan’s departure comes as the first major decision regarding Torey Lovullo’s staff since the manager signed a two-year extension last Thursday. Lovullo hinted that his coaching staff may not look the same next season when speaking to reporters at a press conference after signing his extension.

“I’m going to have some conversations, and I need to think through some things very clearly,” Lovullo said. “To be honest with you, I haven’t thought about it at all, and I want to be fair to that group. I told them on the last day in San Diego that I didn’t know what was happening with me, and once I figured that out, I will start to move downfield with the next group of decisions.”

Whoever the incoming pitching coach is will become the club’s fifth since Lovullo was hired prior to the 2017 season.

With key pitchers like Michael Soroka, Kevin Ginkel, Taylor Clarke and Gallen due to hit free agency, it’s possible that the sudden pitching coach change could have an immediate impact on what the future staff looks like.

Related

Who were the Diamondbacks’ top minor leaguer players in 2026?Diamondbacks moving on from longtime broadcaster Steve Berthiaume2 years means 2 years for Torey Lovullo contract, even with lockout potential5 questions the Diamondbacks need to answer this offseasonWhat is Ketel Marte’s future in Arizona? Here’s what each D-backs decisionmaker saidDiamondbacks owner Ken Kendrick expects payroll to be lower next season