Things have gone from bad to worse for Arizona Diamondbacks ace Corbin Burnes. He had a setback when trying to work his way back to the mound. 

Burnes suffered a teres major strain in his recovery from elbow surgery, according to Nick Piecoro of The Arizona Republic. Burnes underwent elbow surgery in June 2025. 

He was initially expected to return around the All-Star break, but his return has now been pushed to September. 

The setback has forced him to be pulled from his throwing progression, delaying his return to the mound significantly this season. 

The setback he faced was also unrelated to his Tommy John surgery but caused tightness in his throwing side that impacted his pitch movement and velocity.

Corbin Burnes suffered a teres major strain in his recovery from elbow surgery and will be shut down, per @nickpiecoro.

Burnes was expected back around the All-Star break but the hope now is that he can return sometime in September. pic.twitter.com/X6gBYmRv95

Injuries continue to haunt Corbin Burnes

It is a significant blow because when he is healthy, Burnes is a frontline starter. But the ace has not been able to demonstrate his elite pitching with the Diamondbacks because of severe injuries. 

The Diamondbacks are carefully monitoring to ensure that when Burnes returns, he is in prime health. The 31-year-old is at the outset of his hefty six-year, $210 million contract, but has made only 11 starts across the first two years. 

Before signing as a free agent with the Diamondbacks, Burnes was highly regarded as one of the most formidable starters in MLB. He boasted a 2.92 ERA with the Baltimore Orioles in 2024 and won the NL Cy Young Award in 2021 with the Milwaukee Brewers.

With the Diamondbacks (32-28) only hanging around to make a potential postseason push, it may be best to even save his arm for next season.