RB Jordan Mason filled in admirably to start the year, but he was hit with a shoulder injury in Week 6 that he battled until McCaffrey’s return in Week 10. McCaffrey and Mason were both hurt in a Week 13 loss to the Buffalo Bills, which pushed rookie fourth-round pick RB Isaac Guerendo into the starting role.

Guerendo has rushed for 381 yards and four touchdowns this season. The 49ers are also likely to again be without left tackle Trent Williams as well Sunday. Williams has missed the

San Francisco 49ers running back Isaac Guerendo appeared on Wednesday's injury report due to a hamstring issue sustained during last week's game against