The San Francisco 49ers will be without their top two running backs, Christian McCaffrey and Jordan Mason, as both are headed to injured reserve. McCaffrey is dealing with a PCL injury in his right knee, which is expected to require a six-week recovery period, while Mason has a high ankle sprain. Rookie Isaac Guerendo will take over as the starting running back for the 49ers, who are struggling at 5-7 after a recent loss to the Buffalo Bills.
- The 49ers' running back situation is dire with both McCaffrey and Mason out.
- Isaac Guerendo will be the starting RB moving forward.