Police in Las Vegas said Monday they’re investigating allegations that a fan in the stands struck Cardinals quarterback Kyler Murray amid celebrations of Arizona’s 29–23 overtime victory over the Raiders.

Murray was high-fiving front-row spectators at Allegiant Stadium following Byron Murphy Jr.’s game-ending fumble return on Sunday when a man appeared to reach out and smack Murray in the face with an open hand.

Video showed Murray appear stunned, but not injured, then attempted to identify the attacker in the mostly happy crowd.

Officer Larry Hadfield, a Las Vegas police spokesman, confirmed that a battery complaint was made about 6:30 p.m. at the stadium. The report was not immediately available.