Zac Gallen to Make Final Spring Start for the Diamondbacks

The Diamondbacks Ace for the last six seasons gets ready to embark on his seventh season with Arizona.

Feb 19, 2025; Scottsdale, AZ, USA; Arizona Diamondbacks pitcher Zac Gallen (23) poses for a portrait for MLB Media Day at Salt River Fields. Mandatory Credit: Allan Henry-Imagn Images | Allan Henry-Imagn Images

The Arizona Diamondbacks host the Athletics on Thursday at Salt River Fields, with a game time of 1:10 p.m. The game can be found on Dbacks.com as an MLB audio webcast.

This is the fourth and final matchup between the two teams this Spring Training. The D-backs split a two-game series with the A's in Las Vegas March 8 and 9, and then followed that up by beating the Athletics 5-2 on March 12.

Zac Gallen will start for what could be his final in-game tuneup before the start of the regular season on March 27. Manager Torey Lovullo has yet to name the Opening Day starter, and is expected to do so at noon on Thursday.

Gallen has been a Diamondback since the 2019 trade deadline, coming over from the Miami Marlins in exchange for infielder Jazz Chisholm. In 136 games with Arizona Gallen has a 52-34 record with a 3.32 ERA, or 128 ERA+. Gallen will be a free agent at the end of 2025. His agent is Scott Boras.

If the Opening Day start goes to Gallen, then he would be working on six days rest for the opener. If the start goes to Corbin Burnes then it remains to be seen what Gallen's throwing program could be to make the second start of the year on seven days' rest. In either case it may require an extra bullpen session beyond the normal one side session between starts pitchers normally throw.

Gallen's most recent outing took place March 14 in a minor league game on the backfields as the D-backs had to rearrange the pitcher schedules due to a rainout. He threw four innings, giving up one run on two hits and two walks. Expect him to try to throw five innings and get his pitch count up over 65.

Starting for the Athletics will be Joey Estes, a 23-year-old right-hander who made his major league debut in 2023, and thew 128 innings in 2024, posting a 7-9 record with a 5.01 ERA.

Estes walked very few batters, just 27 last year, and struck out 92, but he gave up 23 homers. His fastball clocks in around 92 MPH on average, and he throws a sweeper, slider and changeup.

Lineups

Athletics at Diamondbacks Lineups March 20 | Jack Sommers

Torey Lovullo and the coaching staff will get a look at two middle infield non-roster invitees vying for the utility spot for opening day. Garrett Hampson will play shortstop and Ildemaro Vargas plays second base.

Randal Grichuk is back in the lineup and in left field after missing a couple of games with a sore left ankle. That is the same ankle the outfielder had surgery on in January of 2023. Grichuk said it just came on suddenly, but if it had been the regular season, he would have played sooner.

Top-rated prospect Demetrio Crisantes gets another start in a major league game, this time at third base. He is 2-for-9 with a gap-splitting double so far this spring. Fans can expect to get a look at another top prospect, Tommy Troy, coming off the bench later in the game.

The top high-leverage bullpen options for Lovullo are expected to pitch following Gallen, including A.J. Puk, Kevin Ginkel, and Justin Martinez. On Wednesday Lovullo announced that the team will not designate a closer to start the season. While Lovullo prefers to have a closer, for now they will go by matchups until somebody emerges to take control of the role.

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