Forte sustained the injury in the third quarter after taking a hit from Minnesota Vikings safety Harrison Smith.
Jay Glazer of Fox Sports reports the team does not believe Forte injured his ACL on the play.
The 29-year-old running back was able to walk off the field on his own and headed into the locker room. Forte had 10 carries for 41 yards and caught four receptions for 28 yards before leaving the game.
Rookie Jeremy Langford filled in for Forte and carried 12 times for 46 yards.
Forte has missed on five games in his eight-year NFL career. He hasn’t missed a game since an ankle injury sidelined him in Week 3 of the 2012 season.