D-backs Reportedly Making Major Change to Pitching Strategy

The Arizona Diamondbacks are making another change to their pitching approach, according to a recent report from The Arizona Republic's Nick Piecoro.

Piecoro reported that former All-Star pitcher Dan Haren, who had been Arizona's pitching strategist for nearly a decade is parting with the organization, mutually.

But the changes are not limited to just a shift in personnel. The Diamondbacks are changing the way they create gameplans for opposing hitters at the major league level.

Arizona Diamondbacks Making Change to Pitching Strategy

Arizona Diamondbacks pitcher Corbin Burnes (back) and pitching coach Brian Kaplan watch pitcher Merrill Kelly (29) throw during spring training workouts on Feb. 10, 2026, at Salt River Fields in Scottsdale. | Rob Schumacher/The Republic / USA TODAY NETWORK via Imagn Images

Per Piecoro's article, the D-backs are shifting their gameplan focus from being centered around the opposing hitters' weaknesses. Instead, they will be more concerned with maximizing the strengths of their own pitchers.

“We’re not pushing [hitters' weaknesses] aside; we have plenty of resources to be very well-prepared for that," Kaplan told Piecoro. "But just centering a little more on our own guys and improving the stuff and the execution and just their overall arsenals.”

Pitching coach Brian Kaplan told Piecoro they began to make that change in the latter end of the 2025 season. Arizona's team ERA in the first half of 2025 was 4.65. It fell to 4.26 in the second half. Their overall 4.49 ERA was the eighth-worst in the major leagues.

Kaplan will reportedly take over gameplanning duties, alongside run-prevention coordinator Sharif Othman.

These changes are the second wave of alterations to the D-backs' internal pitching philosophies. Earlier in the offseason, they hired former Pittsburgh Pirates director of pitching development Jeremy Bleich to take on an assistant GM role, focused on the oversight of Arizona's recently-struggling pitching development system.

Even preceding Bleich's hire, the D-backs knew they wanted to change the way they developed pitchers. Piecoro also reported an intent to begin a more aggressive process, looking to emphasize velocity to a slightly higher degree.

While there have been some success stories, most notably the likes of Ryne Nelson and Justin Martinez, Arizona had, in general, not been able to construct a consistent pipeline of MLB-ready arms.

That deficiency was felt to an exceptional degree in 2025, as injuries to both the starting rotation and bullpen devastated a group of already-underperforming arms.

The D-backs also brought in a wealth of young arms during 2025, both at the deadline and through the MLB draft — in hopes of replenishing that system. There is a clear investment from Arizona in both adding talent and making adjustments where deficiencies may lie.