Running back Christian McCaffrey will go on injured reserve with a posterior cruciate ligament strain that may not need surgery, but is serious enough to sideline him for the season. To make matters worse, Jordan Mason, the 49ers’ leading rusher, will also “most likely” go on IR and could miss the remainder of the season.

The San Francisco 49ers' dreadful season got worse in Week 13 when running backs Christian McCaffrey and Jordan Mason both suffered injuries that will land the RBs on IR. McCaffrey will miss at least six weeks with a PCL injury in his knee,