AP

Raiders rookie quarterback Derek Carr, who was knocked from Friday’s preseason matchup vs. Detroit, has sustained a concussion, coach Dennis Allen said after the game, according to multiple media outlets.

Carr was hit hard by Lions defensive end Larry Webster on a fourth quarter scramble, with Webster’s weight landing on Carr’s upper back. Carr also has rib soreness, Allen said, according to ESPN’s Paul Gutierrez.

Austin Murphy of Sports Illustrated reported Carr told a team doctor he “heard a crunch” as he was hit.

In about two quarters of action, Carr showed some potential, completing 9-of-16 passes for 109 yards and a touchdown. The second-round pick from Fresno State was relieved by Matt McGloin, who threw a 16-yard TD pass to Brice Butler with six seconds left to give Oakland a 27-26 victory.

Carr will have to go through NFL-mandated concussion testing to be cleared to return to action. The Raiders’ next preseason game is Friday, August 22 in Green Bay.