Diamondbacks Release Young Reliever Christian Montes De Oca

PHOENIX — The Arizona Diamondbacks have officially released right-handed reliever Christian Montes De Oca, according to transaction logs on his player page, ending the 26-year-old’s brief tenure with the organization.

Montes De Oca had been outrighted off the 40-man roster earlier in the offseason and never regained a foothold in the club’s plans. Signed as a developmental arm, he reached the majors for the first time in 2025 but managed only one appearance before a lower-back injury and elbow discomfort shut him down for the remainder of the year.

The hard-thrower impressed in his lone big-league outing, firing 2.2 scoreless innings and collecting his first two MLB strikeouts on June 7. That outing capped a rapid rise that began with a May 16 promotion, though he did not appear in a game during that initial stint.

At Triple-A Reno, Montes De Oca posted a 4.07 ERA across 17 games, striking out 26 batters in 24.1 innings. That mark is considered well above-average in the hitter-friendly Pacific Coast League, thanks to an upper-90s fastball that generated swings and misses.

Despite the promise, the combination of back surgery and elbow issues clouded his future. The Diamondbacks now part ways with the reliever, leaving them with a surplus of bullpen candidates vying for spots in 2026. While a return on a minor-league deal remains possible, Montes De Oca was not projected to crack the Opening Day relief corps.

Arizona enters spring training with an open competition for the final eight bullpen slots. Closer candidates Justin Martinez and A.J. Puk are recovering from Tommy John surgery, thrusting Kevin Ginkel, Ryan Thompson, and a healthy Paul Sewald into high-leverage roles.

Manager Torey Lovullo has emphasized merit over pedigree as pitchers report to camp.

What I’ve told every single one of them is there’s eight spots open, and you’ve got to go out there and earn it, Lovullo said. I want you to have that earning mentality. Nothing’s going to be handed to you.

The release of Montes De Oca trims the D-backs’ relief depth, yet the organization believes its stockpile of arms can absorb the loss as it eyes a return to postseason contention in 2026.