Mason rushed five times for 27 yards and a touchdown but wasn't targeted in Sunday's 19-17 loss to the Browns.
Mason took over as San Francisco's lead back after Christian McCaffrey (oblique/rib) exited in the second half. The 24-year-old running back out of Georgia Tech gave the 49ers a 17-13 lead with an eight-yard touchdown run in the fourth quarter, but Cleveland responded with a pair of field goals to hand the 49ers their first loss of the season. Elijah Mitchell (knee) returned from a two-game absence but had just minus-3 yards on two carries. If McCaffrey is unable to suit up against the Vikings in Week 7, Mason would likely lead San Francisco's backfield over Mitchell.