Chiefs LB Justin Houston leaves game with knee sprain

Chiefs All-Pro linebacker Justin Houston was ruled out with a knee injury and head coach Andy Reid said he sustained a knee sprain after the game. 

Bills rookie running back Karlos Williams is questionable to return after being injured in the first quarter.

Houston limped off the field with a left knee injury after getting tripped by a teammate while chasing a play. He was face-down on the turf for several minutes before he was eventually helped to his feet.

Houston, who had 22 sacks last season, was replaced by Frank Zombo. Houston has 7 1/2 sacks this year.

Williams hurt his shoulder late in the first quarter. He has five rushing touchdowns this season.