Bears RB Matt Forté left Sunday's game against the Chiefs with a knee injury and will not return.
Forté took a helmet to the knee from Chiefs ILB Derrick Johnson on the Bears' second drive of the game. He had five carries for 12 yards before exiting.
Marion Barber will take over as the team's primary back. Forté entered Sunday third in the NFL with 985 rushing yards. The Bears third-string running back is Kahlil Bell, who has just 11 rushing attempts all season.