The Kansas City Chiefs placed Justin Houston on the physically unable to perform list on Tuesday and placed fellow linebacker Josh Mauga on injured reserve.
Houston, who must sit out the first six games this season, led the league with 22 sacks in 2014 before a knee injury limited him to just 11 contests the following year. The 27-yar-old finished the 2015 campaign with 30 tackles, 7.5 sacks and two interceptions.