UPDATE: Texans Andre Johnson goes down with knee injury

With 6:10 left in the 2nd quarter against the Pittsburgh Steelers, Houston Texans WR Andre Johnson just fell to the ground clutching his right knee.

Catching a pass from QB Matt Schaub, Johnson made a cut and, untouched, fell to the ground grabbing the knee.

Stay tuned for an update as to his condition, which presumably will end his day at a minimum.