After a few months away from the Diamondbacks, Merrill Kelly will return to the team in 2026. Kelly will reportedly rejoin the team on a two-year deal after a strong run in Arizona and an uneven one with the Texas Rangers.
A Look at Kelly
Before 2025, the Diamondbacks were the only MLB team that Merrill Kelly knew. A draft pick of the Rays way back in 2010, Kelly gained notoriety in the KBO during the 2010s and earned a spot on the Diamondbacks in 2019. From 2019 through 2025, Kelly was a steady innings eater, as he threw at least 130 innings in all of those campaigns except for 2010 (pandemic) and 2024 (injury).
Kelly pitched very well with Arizona in 2025, as he averaged almost a strikeout per inning and owned a sub-4.00 ERA. His ERA ticked up to 4.23 with Texas, the team that acquired him at the deadline for Kohl Drake and David Hagaman. Kelly conceded nine home runs over 55.1 IP with the Rangers.
The 37-year-old remained one of the premier pitchers in the game when it came to inducing chases out of the zone. Kelly ranked fifth in the Majors last season (min. 700 pitches thrown) in Chase% (32.8%), behind only Aaron Nola, Bailey Ober, Spencer Schwellenbach, and Tarik Skubal.
He does all of that without throwing particularly hard. Kelly lives with a low-90s sinker and four-seamer, the latter of which will get dinged up even though he also induces a fair amount of swings and misses off the four-seamer. Some of that can be attributed to arm angle. However, the changeup is what has made Kelly a tough pitcher to face.
The changeup doesn’t have a ton of velocity separation off the four-seamer and sinker. It only averages about four MPH off, not as much as the seven to 10 MPH sweet spot. What Kelly can do, though, is work that pitch effectively down and out of the zone, which often leads to chases out and topped-off contact.
For reference, Kelly’s changeup had the fifth-best Chase% (47.7%) last season. That number was also fifth-best in the Majors (min. 90 changeups thrown). Raisel Iglesias, the league leader (48.7%), Tarik Skubal, Nabil Crismatt, and Pierson Ohl were the only pitchers with a better rate.
Additionally, Kelly has other weapons in his arsenal. He’ll often throw a cutter, as well as a slider (mainly against RHH) and curveball.
Kelly ranked among the upper echelon of the league in wOBA (.288) in this past season. That number was 28th-best among starters with at least 100 innings thrown.
Per multiple reports, the Diamondbacks will bring back Merrill Kelly on a two-year deal worth $40MM.
Analysis
This move made too much sense for both sides.
Kelly is an Arizona boy. He went to Arizona State and went to high school in Scottsdale. Plus, he’s had success for the D-Backs throughout his career.
As for the Diamondbacks, Kelly’s return does help out a rotation that won’t have Corbin Burnes next season. Zac Gallen, the team’s ace for much of the 2020s, went to free agency in November.
Kelly joins Michael Soroka as recently-signed players for the Diamondbacks. The move also rounds out a rotation that, presently, will likely also include Brandon Pfaadt, Ryne Nelson, and Eduardo Rodriguez.
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