Blake Walston to make first major league start in series finale vs. Marlins

After the Diamondbacks’ 3-2 win over the Miami Marlins Saturday night, manager Torey Lovullo announced that left-hander Blake Walston will make his first major league start. He will fill the rotation spot vacated when they optioned Slade Cecconi to Triple-A Reno on Wednesday.

Walston, 22, has one major league appearance to his name. On May 1, he made a long relief appearance for the Diamondbacks against the Dodgers. He went 3 2/3 innings, allowing two runs on three hits and four walks while striking out five. He flashed mid-90s velocity early in the appearance and held his own against one of the toughest lineups in baseball.

To make room for Walston on the active roster, the Diamondbacks have designated reliever Matt Bowman for assignment. Arizona’s 40-man roster sits at 39 players.

Walston will have a chance to stake his claim to a rotation spot while the Diamondbacks wait for Merrill Kelly and Eduardo Rodríguez to finish rehabbing their shoulder injuries. They got encouraging news on Kelly’s MRI and Rodriguez is progressing in his throwing program, and is out to 60 feet.

Bowman, 32, appeared in four games with the Diamondbacks after being acquired earlier this month. He pitched to a 8.10 ERA/4.78 FIP with four strikeouts and two walks in 6 2/3 innings in most low-leverage innings. Arizona acquired him at a time where their bullpen was gassed and struggling with injuries. Thanks to more consistent performances from the starting rotation, plus the return of Paul Sewald, the bullpen has been in better shape of late.