Froholdt is in league concussion protocol Monday, Darren Urban of the Cardinals' official site reports.
Froholdt played all 51 of the Cardinals' offensive snaps during Sunday's game at Seattle, but he may have suffered a concussion somewhere along the way. He'll need to clear the NFL's five-step concussion protocol, which includes getting clearance from an independent neurologist, before he'll be able to return to game action. With Jon Gaines nursing an ankle injury, Arizona could be forced to turn to 2025 sixth-rounder Hayden Conner, who has limited experience, for reps at center.