Montgomery (right leg) was carted to the locker room during Sunday's game against the Seahawks, Dave Birkett of the Detroit Free Press reports.
Montgomery got his right leg twisted up by a Seattle defender at the end of a seven-yard catch late in the third quarter. The nature of the injury isn't known, but he had 16 carries for 67 yards and one touchdown and the aforementioned reception at the time of his departure. Rookie Jahmyr Gibbs will take over the Lions backfield for the time being.