Christian Montes De Oca during photo day at Salt River Fields at Talking Stick on Feb. 21, 2024. Rob Schumacher/The Republic / USA TODAY NETWORK

Diamondbacks Outright Reliever to Triple-A

Originally posted on Arizona Diamondbacks on SI
By Alex D'Agostino | Last updated Nov 17, 2025 7:01 PM ET

The Arizona Diamondbacks have made a roster move. According to their transaction log, right-handed reliever Christian Montes De Oca has been outrighted to Triple-A Reno, freeing up a spot on the 40-man roster.

Montes De Oca, 26, spent limited time on the D-backs' roster in 2025 before going down with an injury that claimed the remainder of his season.

With the Rule 5 Draft protection deadline arriving on Tuesday, Arizona now has three free spots on the 40-man roster if they want to protect any of their Rule 5-eligbile prospects.

For the full breakdown of the D-backs' Rule 5 roster crunch, check out Jack Sommers' article below:

Arizona Diamondbacks Outright Christian Montes De Oca

Rob Schumacher/The Republic / USA TODAY NETWORK

Montes De Oca was called up from Triple-A Reno for the first time on May 16, but was optioned back to the minors just a week later, without making his MLB debut.

It was a strange set of circumstances, and with an already-depleted bullpen, was odd to see the right-hander make no appearances in his first stint with the big league club.

But eventually, Montes De Oca was recalled, and made quite the first impression in the majors. Though it came in a blowout loss to the Cincinnati Reds, Montes De Oca tossed 2.2 scoreless innings on June 7 without allowing a base hit.

He walked one batter and struck out two, throwing 27 of his 46 pitches for strikes.

But not long following, he suffered an elbow injury that would hold him out of the remainder of the 2025 season at any level. He was placed on the 15-day IL with right elbow inflammation on June 10, and found himself on the 60-day IL nine days later.

Montes De Oca had a high level of success in Triple-A in 2025, throwing to a 4.07 ERA and 3.76 FIP with the Aces. For the extremely hitter-friendly environment, that is a well-above-average figure.

He profiles as more of a power righty with the ability to provide multiple innings. If not for the injury, he may have seen his role grow with the D-backs throughout the course of the season.

For now, he's off the 40-man roster. Arizona will likely add names like Kohl Drake and Mitch Bratt (both returns from the Merrill Kelly trade) to the 40-man roster to protect them from being snatched in the Rule 5 Draft.

Arizona's bullpen, meanwhile, is still in need of some upgrades as they await the return of A.J. Puk and Justin Martinez from their respective Tommy John surgeries. The D-backs have plenty of roster holes to fill this offseason, but pitching is the highest of priorities.