The Houston Texans' defense has taken a pair of major hits in quick succession.
Watt suffered the injury on a play in which he lost his footing, and was helped off the field.
The Texans' defensive anchor was briefly examined, then carted off to the locker room. The extent of the injury has not yet been confirmed.
The development came moments after rush end Whitney Mercilus suffered a chest injury on the same series. He's since been ruled out for the remainder of Sunday's tilt, according to Aaron Wilson of the Houston Chronicle.