Watt, who is arguably one of the best defensive ends in the NFL, lasted barely 10 minutes in the first quarter.
There was very little contact in play when the Chiefs star went down clutching his left knee.
Medical staff came rushing to the scene to attend to him, but they were forced to bring him off the field.
He was left grimacing in pain and he could barely put any pressure on his leg as he was immediately taken for treatment to assess the severity of the damage.
Following his assessment, the Texans confirmed on Twitter he will play no further part in the game after being carted off to the locker room.
The Texans’ tweeted: “DE J.J. Watt is OUT with a knee injury.”
It was later announced that he was rushed to hospital to find out the full extent of his injury.
He was also hobbling to the ambulance on crutches.
Watt, 28, missed 13 games last season after having to undergo back surgery and was placed on injury reserve as a result.
And he could be out for the majority of the season once again.