San Francisco head coach Kyle Shanahan said Monday that Mason is "doing great" in his recovery from a tight hamstring, per David Lombardi of The Athletic.
Mason played in last Saturday's win over Washington but was limited to special teams. Tyrion Davis-Price took over the backup RB role behind Christian McCaffrey in that contest, but Mason is expected to again work behind McCaffrey in Week 17 now that he is showing improvement. Mason had been very effective in his previous three games prior to Saturday, tallying 171 rushing yards on 23 carries.