The Phillies lose Brian Kaplan, who joins the Diamondbacks as pitching coach

On By Littum

The Philadelphia Phillies have valued continuity ever since they broke a decade-long postseason drought in 2022 — and that meant keeping most of the forces behind the scenes in place. They promoted people and retained them with higher wages. But they were unable to retain a key member of the organization, Brian Kaplan, who left Tuesday to become the pitching coach of the Arizona Diamondbacks.

Kaplan, who served as the club’s assistant pitching coach and director of pitching, was instrumental in building a program that helped the Phillies gain momentum on the mound. Caleb Cotham, the club’s pitching coach, will remain. He signed a multi-year deal at the club last year to stay on board.

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

Free-agent pitchers and their agents raved about Zoom meetings they had in recent offseasons with Cotham and Kaplan, working together to create improvement plans. Kaplan had never worked for a team before taking a job with the Phillies in 2022 and divesting his ownership of 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 the Painters’ pitching progressions as he worked his way back from Tommy John surgery in July 2023.

Kaplan helped the Phillies make strides in biomechanics and oversaw sweeping changes to how the Phillies develop pitchers. The Phillies have seen some returns there; They have traded under-the-radar pitching prospects in trades over the past two years. But the club hasn’t used much draft capital in recent seasons to acquire pitchers.

Kaplan joined the Phillies because he had a strong relationship with Sam Fuld, who once coached as a player with Kaplan and recruited him to Philadelphia. The Phillies announced last week that Fuld will transition to president of business operations in 2026 while still having influence over baseball decisions.

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

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(Photo: Mike Ehrmann/Getty Images)