Mason rushed eight times for 28 yards and wasn't targeted as a receiver in Sunday's 38-13 win over Arizona.
The 49ers welcomed back Elijah Mitchell (knee) from injured reserve, but Mason still received 14 snaps on offense in the regular-season finale. The Georgia Tech product did an admirable job backing up Christian McCaffrey in Mitchell's absence this season, racking up 258 yards on 6.0 yards per carry in limited action over the course of his rookie campaign. Mason will likely see his role limited to special-teams duty in the wild-card round matchup with Seattle this weekend with San Francisco's backfield now at full strength.