Mountcastle (foot) did some running Saturday, Roch Kubatko of MASNSports.com reports.
Mountcastle has been out of action since April 11 due to a fractured left foot. He is currently on the 60-day IL, and though he's already eligible to be reinstated, the 29-year-old isn't expected to be activated until late June or early July. Given that he's now back to running, it sounds like Mountcastle is progressing well toward that timeline.