Diamondbacks Officially Reveal New Opening Day Starter

Arizona has made its decision.

Apr 4, 2025; Washington, District of Columbia, USA; A detailed view of an Arizona Diamondbacks hat at the game between the Washington Nationals and the Arizona Diamondbacks at Nationals Park. Mandatory Credit: Reggie Hildred-Imagn Images | Reggie Hildred-Imagn Images

The Arizona Diamondbacks have officially named their (new) opening day starter, according to various reports. Right-hander and returning former ace Zac Gallen will get the nod opening the year at Dodger Stadium in Los Angeles on March 26.

Gallen will take the mound on opening day for the fourth consecutive season as a member of the D-backs. He will be just the third player in franchise history to do so, joining Randy Johnson from 1999-2004 and Brandon Webb from 2006-2009.

"It's just an honor, it's humbling," Gallen said (via Jose Romero of AZCentral). "Four is crazy, just kind of puts into perspective how long I've been here. It's nice."

Arizona Diamondbacks' Zac Gallen Gets Opening Day Start

Feb 18, 2026; Scottsdale, AZ, USA; Arizona Diamondbacks pitcher Zac Gallen (23) poses for a photo for MLB media day at Salt River Fields at Talking Stick. Mandatory Credit: Allan Henry-Imagn Images | Allan Henry-Imagn Images

Gallen will replace right-hander Merrill Kelly, who was initially given the honor of making his first-ever opening day start.

Kelly was knocked off his schedule as a result of mid-back tightness from intercostal nerve irritation, however, and was therefore unable to ramp up in time to make the start in LA.

Gallen re-signed with Arizona this offseason on a one-year deal worth the $22.025 million equivalent of the qualifying offer he rejected. $14 million of that is deferred. Gallen turned down multi-year offers elsewhere after repeatedly expressing his desire to return to the D-backs.

"All the way down, ownership, management, even coaches, the attitudes and the personalities and the people here. That's what really draws you in. And the culture here is a culture that to me, I think, is second to none," Gallen said after signing at the beginning of spring training.

The right-hander pitched to a career-worst 4.83 ERA in 2025, but owns a career 3.58 ERA, spending parts of seven seasons with the D-backs. He will seek a bounce-back season.

The Diamondbacks do not yet have a concrete order for their starting rotation, with both Eduardo Rodriguez and Michael Soroka still pitching in the World Baseball Classic. It is still unknown if Kelly will be built up enough to completely avoid a stint on the injured list.

Gallen came into spring training slightly behind schedule, but will still be able to ramp up enough to make the start on opening day. The right-hander has looked sharp in his spring training action thus far, making three scoreless starts.

Most recently, Gallen threw three clean, scoreless innings against the Seattle Mariners, complete with three strikeouts. His four-seam fastball fell just shy of 96 MPH.