D-backs pitching coach Brian Kaplan will not return for 2027 season

What happened

The Arizona Diamondbacks will not retain pitching coach Brian Kaplan when his two-year tenure with the club concludes, MLB.com's Steve Gilbert reported. Kaplan joined the organization two seasons ago and will not be back for 2027, making him the first departure from Arizona's coaching staff as the franchise turns its attention to the offseason.

Why it matters

Pitching coach transitions carry real operational weight. The person who runs a staff's development program, manages workloads, and shapes how pitchers are deployed from start to finish is not a background figure — and finding the right one is, to put it gently, not a solved problem across the industry. For Arizona, the timing layers this search on top of an already active offseason agenda.

The Kaplan news arrives in the same week that Torey Lovullo locked in a new two-year contract to continue managing the Diamondbacks, per reporting from earlier this week. That extension anchors the dugout and gives the front office a stable foundation from which to rebuild the coaching staff around him. Lovullo will have meaningful input into who fills the pitching coach role next, and the continuity at the managerial level at least removes one variable from what is shaping up to be a busy winter.

The departure also lands against a backdrop of genuine pitching intrigue. Earlier this week, Posterior Wire covered Eduardo Rodriguez's 2026 season, in which he posted a 2.89 ERA for Arizona despite estimators projecting something closer to 4.4 — a gap driven by elite pitch location, measured at 109 Location+, rather than raw stuff. That kind of nuanced outcome raises natural questions about how a pitching coach's influence registers in a staff's results. Whether Kaplan's departure is connected to any broader performance assessments is not something Steve Gilbert's reporting addresses, and the desk will not speculate. What is clear is that whoever steps into the role next will inherit a staff with at least one pitcher whose success story is more about precision than power.

Where the club stands

Arizona finished 2026 at 86-76 (.531), third in the NL West and 14 games back of the division leader. The Diamondbacks enter the offseason eliminated from both the division race and the Wild Card race, sitting fourth in Wild Card positioning at 2.0 games relative to the cut line, and carrying a two-game losing streak into the winter.

That record — competitive but not postseason-bound — is the organizational context in which this coaching change lands. An 86-win club is not rebuilding, but it is also not a team that can afford to treat any part of its infrastructure as a placeholder. The pitching staff's performance next season will be shaped in part by whoever steps into Kaplan's role, and the front office will be conducting that search while simultaneously addressing other roster priorities.

The Diamondbacks have real work ahead on multiple fronts. Per reporting from earlier this week, D-backs GM Hazen confirmed the club will prioritize adding left-handed bats in the offseason, targeting upgrades at first base and designated hitter after struggling against right-handed pitching in 2026. That offensive retooling is now running in parallel with a pitching staff coaching search — two significant items on the same offseason to-do list.

The situation around Ketel Marte adds another layer of uncertainty. Diamondbacks executives signaled earlier this week that Marte's future with Arizona is uncertain following conduct and absence issues in 2025, with a trade described as possible despite Marte holding full no-trade rights. How that situation resolves will affect the roster's shape and, by extension, what the next pitching coach inherits in terms of overall team construction.

Lovullo's two-year extension is the clearest stabilizing signal the organization has sent this week. Everything else — the coaching staff, the lineup, the Marte question — remains in motion.

What we don't know yet

MLB.com's reporting does not identify any candidates for the pitching coach vacancy, nor does it offer a timeline for when Arizona expects to fill the role. It is not known whether the parting was mutually agreed upon, whether the club initiated it, or whether Kaplan has interest in other opportunities around the league. None of those questions are addressed in Steve Gilbert's piece.

The Rodriguez performance story — one of the more interesting pitching narratives to come out of Arizona's 2026 season — raises questions about staff development and coaching philosophy that will presumably factor into the search. But how the front office weighs those considerations is not something the reporting addresses.

What to watch

The pitching coach search is the obvious thread to follow. Given that Lovullo is locked in for two more years, the hire will be made with some runway in mind — this is not a one-year bridge situation, at least not by design. Watch for names to surface as the league's offseason coaching carousel gets moving in earnest.

The Marte situation is the other major storyline. A trade involving a player with full no-trade rights is inherently complicated, and the outcome will reshape Arizona's roster in ways that affect everything downstream, including what the pitching staff is being asked to support. The left-handed bat search at first base and DH will also move quickly once the front office has a clearer picture of the roster's overall direction.

For now, the Diamondbacks are an 86-76 club with a manager locked in, an open pitching coach seat, and a winter's worth of decisions ahead of them. The coaching search is the first piece to resolve. The rest of the offseason will reveal how the others follow.