Belt was diagnosed Monday with a fractured left thumb, Alex Pavlovic of NBC Sports Bay Area reports.
Belt had to leave Sunday's matchup against the Rockies after being drilled by a fastball on the hand, and X-rays failed to bring good news. The timing on Belt's injury couldn't be worse for San Francisco with the postseason right around the corner. He'll meet with team doctors over the next few days to determine the next steps in his recovery and a timetable for a return, per Maria I. Guardado of MLB.com. According to Andrew Baggarly of The Athletic, Belt is expected to be moved to the 10-day injured list for the remainder of the regular season, though a return during the playoffs has not yet been ruled out.