Chicago Bears running back David Montgomery suffered a concussion in Sunday's 24-17 loss to the Tennessee Titans and is in the concussion protocol, coach Matt Nagy announced Monday.
Montgomery leads the Bears with 472 yards rushing this season and also has two rushing touchdowns. He also has 30 receptions for 212 yards and a touchdown.
He left the Sunday's game in the fourth quarter after gaining 30 yards on 14 carries. He also lost a fumble on a screen pass that was returned for a touchdown by Titans cornerback Desmond King.
Ryan Nall replaced Montgomery in Sunday's game and had four catches for 35 yards and a touchdown in the fourth quarter. The team also has used Cordarrelle Patterson in the backfield and has veteran running back Lamar Miller on its practice squad.