Stewart (groin) caught off a pitching machine Monday, the Pittsburgh Post-Gazette's Bill Brink reports.
Stewart has been dealing with left groin discomfort since Friday. However, an MRI came back negative Saturday, and this step in his rehab process may keep him on track to be available for Opening Day. That said, Francisco Cervelli is expected to claim the vast majority of the catching duties this season. The 35-year-old Stewart said he felt fine after catching the machine, but did not really test himself, so his status will remain uncertain until he does.