Phillies lose Brian Kaplan, who joins Diamondbacks as pitching coach

The Philadelphia Phillies have prioritized continuity since breaking a decade-long postseason drought in 2022 — and that meant most of the behind-the-scenes forces had to stay put. They promoted people and retained them with higher salaries. But they couldn’t retain a key member of the organization, Brian Kaplan, who left Tuesday to become pitching coach for the Arizona Diamondbacks.

Kaplan, who served as the club’s assistant pitching coach and pitching director, was instrumental in developing a program that helped the Phillies gain momentum on the mound. Caleb Cotham, the club’s pitching coach, remains. He signed a multi-year contract within the club last year to stay on board.

Kaplan’s departure marks the first time in at least five years that another club has hired a coach from the Phillies’ MLB team.

The #Dbacks have hired Brian Kaplan as pitching coach.

Welcome to Arizona, Brian! 🏜️ pic.twitter.com/HkxvPmEVWf

– Arizona Diamondbacks (@Dbacks) November 12, 2024

Free agent pitchers and their agents raved about the Zoom meetings they had in recent offseasons with Cotham and Kaplan working together to develop improvement plans. Kaplan had never worked for a team until he took a job with the Phillies in 2022 and sold his ownership to Cressey Sports Performance, a Florida training facility popular with major league players.

One of Kaplan’s students at Cressey, Andrew Painter, has become an integral figure in the Phillies’ future. Kaplan and Painter were close; Although the Phillies shifted Kaplan’s focus from player development to the majors, he remained the point person for Painter’s pitching progress while he recovered from Tommy John surgery in July 2023.

Kaplan helped the Phillies make advances in biomechanics and oversaw sweeping changes in the way the Phillies develop pitchers. The Phillies have seen some returns there; They have traded under-the-radar pitching prospects in trades over the last two years. But the club hasn’t spent much draft capital on pitcher acquisitions in recent seasons.

Kaplan came to the Phillies because he had a close relationship with Sam Fuld, who once coached under Kaplan as a player and recruited him to Philadelphia. The Phillies announced last week that Fuld will move to president of business operations in 2026 but will continue to have an influence on baseball decisions.

The Phillies could upgrade from within to compensate for Kaplan’s departure. César Ramos, a former big league reliever who was the bullpen coach in 2024, is well respected within the organization. Ryan Buchter, another former big league reliever, received positive reviews at Triple-A Lehigh Valley in 2024. He could get a promotion to the majors in some capacity.

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(Photo: Mike Ehrmann / Getty Images)