Aug 24, 2025; Arlington, Texas, USA; Texas Rangers starting pitcher Merrill Kelly (23) comes off the field after he pitches against the Cleveland Guardians during the first inning at Globe Life Field. Mandatory Credit: Jerome Miron-Imagn Images Jerome Miron-Imagn Images

Diamondbacks Make Reunion Signing Official

Originally posted on Arizona Diamondbacks on SI
By Alex D'Agostino | Last updated Dec 19, 2025 4:03 PM ET

The deal has been made official. The Arizona Diamondbacks have agreed to a two-year deal with right-handed Merrill Kelly, according to a release from the team.

Kelly's deal, which had been previously reported some time ago, is for $40 million over two years, but with a vesting option for the 2028 season. Should Kelly pitch more than 170 innings, it will trigger for $12 million. If he goes over 185 innings — something he's only done once in his career — it will increase to $14 million.

Diamondbacks Make Merrill Kelly Signing Official

Jerome Miron-Imagn Images

Kelly spent time away from the D-backs' organization for the first time since he came over to MLB in the 2025 season. Arizona traded their long-time veteran righty to the Texas Rangers at the deadline in exchange for a trio of pitching prospects.

Kelly only made 10 starts for the Rangers, but posted a 4.23 ERA in that period — somewhat below the high level he had made his standard with Arizona.

Kelly is entering his age-37 season, so this deal does come with some risk. But he's been an extremely steady and reliable presence in the D-backs' rotation, earning the "Mainstay" moniker as a result.

Despite never being atop national leaderboards, Kelly has managed to pitch to a career 3.77 ERA with peripherals that have generally held up.

The D-backs, more than anything this offseason, were in need of reliable innings coverage. Kelly provides just that, but with the upside of occasional ace-level starts. Very rarely does the veteran righty stumble across truly poor outings, and he can generally be counted on for five-plus innings of quality work, even when he doesn't have his best stuff.

While the D-backs' pitching staff is still in a state of relative disarray, there's something reassuring about having the Mainstay back in the rotation.