The Arizona Diamondbacks have agreed to terms with veteran right-hander Merrill Kelly on a two-year, $40 million deal, pending a physical. Kelly, who was traded to the Texas Rangers at the 2025 deadline, returns to the team where he spent the first six-and-a-half years of his MLB career. The 37-year-old provides stability to Arizona's rotation amid several pitching uncertainties.
Merrill Kelly is returning to the Arizona Diamondbacks after a brief stint with the Texas Rangers. Sources report that the Diamondbacks agreed to a two-year contract worth $40 million with the 37-year-old right-hander on Sunday, December 14, 2025, pending a physical. The club has not yet confirmed the move.
Kelly joined the Diamondbacks in December 2018 on a four-year, $14.5 million deal after spending 2015-2018 with the SK Wyverns in Korea, where he posted a 48-32 record and 3.86 ERA. He made his MLB debut at age 30 in 2019 and quickly became a fixture in the rotation, earning the nickname 'Merrill the Mainstay.' In 172 career starts, Kelly has a 3.77 ERA and 113 ERA+.
In 2025, Kelly went 12-9 with a 3.52 ERA across both teams, including a 3.22 ERA in 18 starts for Arizona before the trade. With the Rangers, he made 10 starts with a 4.23 ERA. He was traded at the deadline for prospects Kohl Drake (No. 6), Mitch Bratt (No. 9), and David Hagaman (No. 15).
A Scottsdale native and Arizona State alum, Kelly expressed his desire to stay with Arizona before the trade. 'These guys know where I stand on being a Diamondback,' he said. 'I love being here. I have always loved being here. I would always be open to being a snake moving forward.'
The signing bolsters Arizona's rotation, which recently added Michael Soroka on a one-year deal. Holdovers include Ryne Nelson, Brandon Pfaadt, and Eduardo Rodriguez, but Zac Gallen is a free agent unlikely to return, and Corbin Burnes is sidelined until after the 2026 All-Star break following Tommy John surgery in June.
Kelly was a key part of the 2023 World Series team, posting a 12-8 record and 3.29 ERA, including a strong Game 2 performance against the Rangers, allowing one run in seven innings.