Bears RB David Montgomery has a concussion

Bears running back David Montgomery has a concussion, coach Matt Nagy said Monday. He was removed from Sunday’s game in the fourth quarter and replaced by Ryan Nall.

The Bears have an extra day before their next game — they play the Vikings on “Monday Night Football.” If Montgomery isn’t cleared in time, the team could turn to former Pro Bowl running back Lamar Miller, who is on their practice squad after missing last season with a knee injury.

“Hopefully he can contribute soon,” said Bears running backs coach Charles London, who mentored Miller when the two were with the Texans.

Montgomery had 14 carries for 30 yards against the Titans and fumbled a screen pass that was returned by the Titans’ Desmond King for a 63-yard touchdown. He was coming off one of his best games of the season, running 21 times for 89 yards and catching two balls for 16 yards against the Saints.

Montgomery was one of two Bears players to suffer an injury in Sunday’s 24-17 loss. Special teams ace Sherrick McManis broke a finger.