Here’s a concerning development for the Athletics with the start of the postseason just days away.

According to Joe Stliglich of CSNBayArea.com Yoenis Cespedes was forced to leave last night’s win over the Mariners in the fourth inning after aggravating his right shoulder. The 27-year-old has been limited to DH duties for the past two weeks but the A’s were hoping to test him in left field throughout the weekend. That’s unlikely to happen now.

Athletics manager Bob Melvin said after the game that there’s a “good chance” Cespedes will sit out tonight’s game at the very least but he’s still hoping to have him available for the postseason. However since he aggravated his shoulder swinging the bat it’s fair to wonder whether he’d even be able to hold up as a DH.