Kansas City Chiefs linebacker Justin Houston has sustained a knee injury during the team's game against the Buffalo Bills at Arrowhead Stadium.
The 2014 sacks leader was forced off the field in the first quarter of the contest, with the team later confirming that he would not be able to return to the game.
The AFC West side have not revealed the extent of the injury suffered by Houston, who has 30 tackles, 7.5 sacks, two interceptions and a forced fumble in 2015.
The Chiefs also lost Eric Fisher to a head injury, while center Mitch Morse was ruled out with a concussion in the fourth quarter.