Diamondbacks GM Explains Not Trading Zac Gallen at Deadline

The MLB Trade Deadline has come and gone, and the Arizona Diamondbacks have opted not to trade former ace Zac Gallen.

The Diamondbacks have done their fair share of deals, sending Josh Naylor and Eugenio Suárez to the Mariners, Randal Grichuk to the Royals, and later trading Gallen's counterpart — right-hander Merrill Kelly — to the Texas Rangers.

Related Content: Diamondbacks' Trade Merrill Kelly to Rangers in Surprise Deal

Arizona also made a surprise last-minute deal to send Shelby Miller and Jordan Montgomery to the Brewers for some salary relief.

But Arizona's long-time former ace was not added onto the fire sale. It was reported that the Red Sox had interest in both Gallen and Kelly, but neither arm ended up heading to Boston.

On Thursday, Diamondbacks' general manager Mike Hazen discussed Gallen's market, and revealed how he came to remain on the roster.

Arizona Diamondbacks Keep Zac Gallen Through Trade Deadline

"I'm a little surprised," Hazen admitted.

"I think what ended up happening, honestly... is there seemed to be a few teams that dropped out here at the last minute, meaning the last few days, that became sellers. And I think that had a material impact on the market," Hazen said.

"We had a decent amount of teams interested, as you can imagine. ... there wasn't much there in terms of what we would be willing to do, make a trade"

Gallen will be a free agent after 2025, and may be a candidate to receive a Qualifying Offer. If Gallen were to turn down that offer and sign a deal with another team, Arizona would receive a compensation Draft pick, potentially even in the first round.

That draft pick carries inherent value, one that teams looking to swing a trade would have had to outweigh with their offers.

"We told teams that, 'you're going to have to clear a bar. There's a value here for us that we have in holding him,' and it just didn't happen," Hazen said.

Gallen has been with the Diamondbacks through the good and the bad times.

He was an invaluable piece of a club that shocked the baseball world with a trip to the World Series in 2023, and helped Arizona crawl out of some of the darkest parts of franchise history.

With that said, he's seen a steady decline since that magical run, and 2025 has been anything but his year.

Through 127 innings (22 starts) this season, Gallen has thrown to a 5.60 ERA. That is the second-worst qualified ERA in the major leagues.

He's looked nothing like the ace that led the D-backs' rotation for two-plus seasons, seeing a steep drop-off in fastball command and overall effectiveness.

Though there were times at which it seemed Gallen was finding his way back to an elite state this season, he simply never recovered fully, and has to shoulder some of the responsibility for causing Arizona to enter a seller's state at the Deadline.

However, Gallen does still has the stuff of a proficient MLB pitcher. There was some thought that a change of scenery might have been what Gallen needed to achieve a high level of execution again, though that change ultimately did not occur.

From 2020-2025 with the D-backs, Gallen pitched to a 3.67 ERA and was worth nearly 16 average WAR. He led the charge to the 2023 World Series, starting in that year's All-Star Game and placing third in the NL Cy Young voting.

Whether or not he can regain his form with the Diamondbacks remains to be seen, though it appears unlikely.

Arizona Diamondbacks Latest News