(CBS DETROIT) – The bad news on the injury front continues for the Detroit Lions.

On Monday, CBS Sports Lead NFL Insider Jonathan Jones reported that running back David Montgomery could miss the rest of the season after suffering a knee injury in Detroit 48:42 defeat to the Buffalo Bills on Sunday. NFL Network’s Ian Rapoport says Montgomery tore his MCL. ESPN’s Adam Schefter reported that Montgomery will be tested this week and get a second opinion.

Montgomery left the game in the second quarter with an apparent knee injury and returned shortly after halftime before exiting again for the remainder of the game.

Montgomery is one half of Detroit’s dynamic backfield alongside Jahmyr Gibbs. The time split between the two was almost equal: Gibbs carried the ball 186 times for 1,047 yards and 11 touchdowns, while Montgomery caught 185 handoffs for 775 yards and 12 scores.

Also on Monday, Rapoport and Schefter reported that defensive tackle Alim McNeill suffered a torn ACL and cornerback Calton Davis II broke his jaw in the loss to the Bills. McNeil is expected to be out for the season, while Davis will undergo surgery and will be out indefinitely.

The Lions also lost defenseman Khalil Dorsey to an ankle injury on Sunday. Dorsey was placed on a backboard and had to be carted off the field after a collision with teammate Ezekiel Turner during pass defense in the second quarter.

Detroit suffered several notable injuries to its defensive players this season. Aidan Hutchinson, Alex Anzalone, Marcus Davenport, Malcolm Rodriguez, John Cominsky, Derrick Barnes, Jalen Reeves-Maybin, Ifeatu Melifonwu, Emmanuel Moseley and Ennis Rakestraw are currently on injured reserve.