The San Francisco 49ers are falling behind the Seattle Seahawks in the NFC West. Losers of three consecutive contests, it was Seattle’s thrilling Week 11 defeat that sent Kyle Shanahan’s squad on their current winless streak. The 49ers are a last-place 5-7, and suffered a massive blow in Sunday’s embarrassing defeat to the Buffalo Bills.

Rookie fourth-round pick Isaac Guerendo seemed to be an afterthought in the San Francisco 49ers backfield with Christian McCaffrey back in the fold. Now McCaffrey is on IR and likely out for the season because of a PCL injury in his knee against the Buffalo Bills.

The San Francisco 49ers made some significant roster moves on Monday, sending their top two running backs to injured reserve. Christian McCaffrey is expected to miss six weeks due to a knee injury, and Jordan Mason is also hitting IR due to an ankle injury.