Breida is questionable to return to Thursday's preseason game against the 49ers with a shoulder injury.
Breida was one of a slew of early injuries for San Francisco on Thursday, with starting tight end George Kittle (shoulder) and defensive lineman Solomon Thomas (head) also forced out. Breida is currently slated as the 49ers' No. 2 running back behind Jerrick McKinnon, but has taken snaps with the first team and made an early impact in camp. The severity of his injury is not yet known, but as long as Breida is out, expect Joe Williams or Raheem Mostert to slide in as San Francisco's second-string running back.