The Chicago Bears have ruled out running back David Montgomery for Monday night's game against the Minnesota Vikings due to a concussion.

Montgomery suffered the injury in Week 9 against the Tennessee Titans and hasn't been practicing this week.

Elevating Lamar Miller from the practice squad in time for Monday's game is an option, head coach Matt Nagy said on Saturday.

"To me, there's an excitement of the possibility of him being able to fill a role for us," Nagy said.

Ryan Nall and Artavis Pierce are also available at running back for the Bears, and the team has been using receiver and returner Cordarrelle Patterson at the position.

Chicago ranks third-last in rushing with 741 yards this season. Montgomery has been struggling in his second year with just 472 rushing yards and one score through nine games. He's averaging 3.6 yards per carry.