HOUSTON -- Houston Texans defensive end J.J. Watt has been ruled out with a knee injury.
He was seen exiting the X-ray room on crutches before leaving the stadium in an ambulance.
Watt injured his leg on the Kansas City Chiefs' first drive of the game. He fell to the ground while engaged in a block on the play.
Watt was helped to the sideline by the Texans' training staff, and he was looked at in the sideline tent before being taken off on a cart.
Watt's younger brother T.