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Merrill Kelly’s newest deal with the Diamondbacks could allow him to pitch 10 seasons in Arizona.
The Arizona Diamondbacks brought back a familiar face to lead their rotation in 2026. After trading Merrill Kelly at the deadline for three pitching prospects, they reunited on a two-year deal.
A reunion always made sense for both the player and team. Kelly has played the majority of his baseball career in the state of Arizona. Before becoming a Diamondback, he pitched at Desert Mountain High School, Yavapai Community College, and Arizona State University.
Kelly is coming off one of the best seasons of his career. Between the Diamondbacks and Texas Rangers, the 37-year-old went 12-9 with a 3.52 ERA over 32 starts. Despite only making 22 starts with Arizona, he ranked second on the club in Wins Above Replacement. Baseball Reference credits him with 3.0 WAR with Arizona, topped only by Ryne Nelson.
With Kelly back in the fold, he’s expected to anchor their new-look rotation. The way his third contract is structured, he has a chance to retire as a Diamondback at the end of the deal.
Merrill Kelly Contract Details Revealed
The Arizona Republic‘s Nick Piecoro reported Kelly agreed to a two-year, $40 million deal on December 14. A couple days later, he reported the deal included a vesting option for the 2028 season. The option vests at $12 million if Kelly logs 170 innings in the 2027 season, but could increase to $14 million if he reaches 185 innings.
Kelly has logged at least 170 innings in three of the past four seasons. It also gives the team protection against injury and/or decline in his Age-38 season.
It marks the right-hander’s third contract with his hometown club. He joined the Diamondbacks on a four-year deal after 2018, then inked an extension that covered the 2023-25 seasons.
The New York Post‘s Jon Heyman reported the full structure of Kelly’s new two-year deal. Here’s how it breaks down.
Signing bonus: $2 million
2026: $17 million salary
2027: $21 million salary
For payroll purposes, Kelly’s at $18 million for 2026 and $22 million for 2027.
One more quirky addition is that Kelly receives four premium seats for every home start over the life of the deal. Those tickets are likely reserved for his family, who he’ll get to be around during the season once again.
In a May 2025 appearance on Burns & Gambo, Kelly stated that one of his goals was to reach 10 years in the major leagues. Entering 2026, he’s exactly at seven years of service time. With two good seasons, he’ll trigger the 2028 option and could spend at least 10 years pitching for Arizona.
While he’ll keep pitching if teams offer him a contract, there’s a good chance this one could be his last. If he triggers the vesting option, he would reach free agency again, not too long after his 40th birthday. It’s difficult to project a pitcher to remain a viable starter at that age, even though Kelly has aged gracefully in his career so far.
Kelly Spurned NL West Rival to Return to Arizona
On December 15, Ken Rosenthal of The Athletic reported that Kelly turned down a three-year offer from a West Coast team. Rosenthal suspects it was a California-based team, eliminating the Seattle Mariners due to their deep rotation.
Rosenthal’s colleague, Dennis Lin, reported on December 19 that the San Diego Padres had a “competitive offer” for Kelly. While there’s nothing that definitively links the two reports together, it’s reasonable to assume that the Padres were that team.
Kelly’s decision to return to the Diamondbacks wasn’t just a familial one; there were also financial benefits. Arizona has lower taxes than California, with the difference mostly impacting his earnings while at home. While the third year of his contract isn’t guaranteed, he has a chance to stretch it into a $52-54 million deal.
With Kelly going back to Arizona, the Padres pivoted to re-sign Michael King. King turned down the qualifying offer but accepted a three-year, $75 million deal to return to San Diego. Considering how events unfolded, both NL West clubs should be happy with the starting pitcher they brought back this offseason.
Michael McDermott Michael McDermott is a writer at Heavy Sports covering the Arizona Diamondbacks and Major League Baseball. Michael has 10 years experience writing about the D-backs and their farm system for AZ Snake Pit, Burn City Sports, and Diamondbacks On SI. More about Michael McDermott
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