Las Vegas police said Monday they are investigating a fan's contact with the quarterback of the NFL's Arizona Cardinals immediately after the team's win Sunday.
The battery investigation concerns an allegation that "a spectator at the stadium struck a professional football player," the police department said by email.
Video shows someone in the stands at Las Vegas' Allegiant Stadium reaching over fans at the end zone barrier and making contact with the face of the Cardinals' Kyler Murray with an open hand.
Murray had just skipped past the end zone and toward the stands to celebrate his team's walk-off win with back-pats and high-fives. He was struck nearly at the moment he had turned back toward the field. He turned back toward the fans anew to face the man, who was not visible.
"A crime report was taken, and the suspect has not been identified," the police department said.
Spokesperson Carl Francis said the NFL Players Association is monitoring the investigation. Murray's representative, the Cardinals and the team's opponent and host Sunday, the Las Vegas Raiders, did not immediately respond to requests for comment.
Arizona defeated Las Vegas 29-23 when cornerback Bryon Murphy Jr. recovered a fumble and returned it for a touchdown in overtime.
In July, Murray agreed to a five-year, $230.5 million deal with the Cardinals that, with goals completed, would make him the second-highest-paid player in the NFL on an annual basis.