The Diamondbacks won’t be getting Corbin Burnes back any time soon.

The Arizona ace, who is working his way back from Tommy John surgery, suffered a shoulder strain during his rehab and will pause his throwing program, manager Torey Lovullo said, according to The Arizona Republic.

Burnes, 31, underwent surgery last June and had been attempting to return by August, but will now likely have to wait until September, per Lovullo. 

“It’s a blow,” Lovullo said. “It’s something that we’re going to have to deal with. It’s just what we do in this game. We’ve got very qualified players in that clubhouse that are going to get some opportunities. We’ve got five really good starting pitchers right now and they’re doing a good job. I want that to continue.”

Corbin Burnes of the Arizona Diamondbacks pitches during the game between the Washington Nationals and the Arizona Diamondbacks at Chase Field on Sunday, June 1, 2025 in Phoenix, Arizona. MLB Photos via Getty Images

Lovullo said Burnes felt “something was a little tight” in his throwing shoulder and underwent an MRI on Monday that showed a strain.

He added that it will be “weeks, not days,” until Burnes can begin throwing again. 

The latest setback is a major blow for the D’backs and Burnes, who signed a six-year, $210 million deal before last season. 

Burnes was one of the top starting pitchers in baseball before coming to Arizona, making four All-Star teams and posting a 2.94 ERA from 2021-24. It was the fifth-lowest ERA in baseball among pitchers with at least 400 innings on the mound over that stretch.

Starting pitcher Corbin Burnes of the Arizona Diamondbacks walks off the field with assistant athletic trainer Max Esposito during the fifth inning against the Washington Nationals at Chase Field on June 1, 2025 in Phoenix, Arizona. Getty Images

He looked the part during his brief stint with the Diamondbacks in 2025, posting a 2.66 across 11 outings before going down.

Despite Burnes’ absence, Arizona is sitting at 32-28, which is tied with the Padres for second place in the National League West heading into Wednesday’s action.