Texans outside linebacker Jadeveon Clowney left the team's season opener against the Washington Redskins late in the second quarter with a knee injury. He was declared out for the second half. Clowney looked visibly upset as he walked into the Texans' locker room with a trainer. Before he left the game, Clowney had one tackle for a loss of nine yards on a reverse to wide receiver DeSean Jackson. ESPN