Sandlin was diagnosed Monday with an upper-back/right shoulder strain and is expected to miss the remainder of the postseason, Zack Meisel of The Athletic reports.
Sandlin left Saturday's Game 2 wild-card round victory over the Rays early with a tight arm, and follow-up tests didn't yield promising news. Cody Morris and Aaron Civale are candidates to join the active roster as replacements for Sandlin ahead of their American League Division Series against the Yankees.