A source who has spoken with Forte told NFL.com and NFL Network's Ian Rapoport the running back has suffered a high ankle sprain, but the Bears do not have a clear timetable for his return. Forte's availability will depend on his pain tolerance, the source said.
"That's why I'm here: They brought me here to pick up where (Forte) left off, if something went wrong," said Bush following Thursday's loss, according to the Chicago Tribune. "It's the insurance plan, I guess. I'll be ready."
Bush brings more of a power game to the backfield than the sure-handed, slick-stepping Forte. Though a different style of back, the Bears run game should be fine if Forte misses games.