Manager Craig Counsell said Mathias is dealing with a "serious" right shoulder injury after undergoing an MRI this week, Adam McCalvy of MLB.com reports.

EDGE Analysis

The 26-year-old suffered the injury Tuesday and figures to be sidelined for the foreseeable future, though the specifics of the injury remain unclear. Mathias was in the mix for a spot on the Opening Day roster but is now likely unavailable.