Prince Amukamara has concussion

ARLINGTON, Texas -- Already thin in the secondary, the New York Giants lost starting cornerback Prince Amukamara to a concussion in the second quarter of their regular-season opener against the Dallas Cowboys on Sunday night.

Amukamara collided, helmet-to-helmet, with safety Ryan Mundy while the two were combining on a tackle shortly before halftime. It was a scary-looking collision, but both players managed to walk off the field and into the locker room on their own power. At the start of the third quarter, the Giants announced that Mundy had been cleared to return but that Amukamara would miss the remainder of the game with a concussion.

The Giants are already without one of their starting safeties, Stevie Brown, who tore his ACL in a preseason game and is out for the year. Brown's injury elevated Mundy to a starting role and rookie Cooper Taylor to the primary backup safety role. With Amukamara out, Aaron Ross took over as the outside cornerback opposite Corey Webster. Terrell Thomas continued to play the slot corner position, as he had been all night.

There is no immediate word on whether Amukamara is expected to miss more time, though he will have to go through the NFL's concussion testing and protocols before being cleared to play next Sunday against the Broncos.