Chicago Bears running back David Montgomery suffered a right ankle injury when he was rolled up on in the first quarter against the Texans.By video, Montgomery appeared to suffer a high-ankle sprain while pass blocking, according to the Pro Football Docs. He may have an MCL sprain as well, but the high-ankle sprain is the bigger concern.He walked off the field and was check in the blue tent, then walked back to the locker room before he was deemed doubtful to return.Montgomery is unlikely to return to the contest and could miss several weeks with the high-ankle sprain, according to our panel of doctors.He will likely undergo an MRI after the game to determine the severity. Montgomery suffered an MCL sprain in his left knee last season and missed four weeks. Khalil Herbert will serve as the main back with Montgomery out.