Walston (elbow) struck out two and allowed one hit in a scoreless inning during a rehab appearance Wednesday with Triple-A Reno.
Walston had been a full-time starter throughout his minor-league career and started in two of his seven appearances during his debut season with the Diamondbacks in 2024 before undergoing Tommy John surgery last spring. While the Diamondbacks may not have closed the door on developing the 25-year-old as a starter, it appears he'll be preparing for a multi-inning relief role for the remainder of the season once he returns from the 60-day injured list. He's been used out of the bullpen for each of his first three rehab appearances with Reno, covering four innings while striking out three and allowing one unearned run on two hits and no walks.