Hooker suffered a concussion during Thursday's 14-3 preseason loss to the Giants, per coach Dan Campbell, Kyle Meinke of MLive.com reports.
Hooker played the first two drives of the second half, completing five of nine passes for 36 yards and adding four rushing attempts for 34 yards before heading to the medical tent to be evaluated for a concussion. Those tests revealed a concussion, which will likely keep Hooker from suiting up in Detroit's next preseason game against the Chiefs next Saturday. Nate Sudfeld started Thursday's game, suggesting that Sudfeld is currently ahead of Hooker in the competition to back up Jared Goff. While Sudfeld struggled Thursday, Hooker will be unable to make up ground until he clears the NFL's concussion protocol.