EAST RUTHERFORD, N.J. - A New Jersey state police sergeant says witnesses to a beating after the Chiefs-Jets game Sunday at MetLife Stadium in East Rutherford told troopers there was no indication the assailants were Kansas City fans.
Earlier, the New York Post reported that a group of Chiefs fans was responsible for the attack.
But State Police Sgt. Brian Polite says the incident "was not a Jets-Chiefs melee."
Thirty-five-year-old Merle Lee of Newton is free on bond, charged with aggravated assault.
Lee was first charged with simple assault but charges were upgraded after 23-year-old James Mohr's condition worsened.
Polite says the Queens, N.Y., resident got into a brief scuffle with some guys and the skirmish broke up on its own. Polite says Lee then "came out of the blue and punched Mohr in the face."
Mohr was reported in fair condition Wednesday at Hackensack University Medical Center.
"This is an unacceptable attack on one of our guests," a Giants Stadium rep told the Post, "and we have been working with the New Jersey State Police to make sure the man arrested is prosecuted to the fullest extent of the law."
Earlier this year, a fight between a Chiefs fan and several Ravens fans at a preseason game in Baltimore was caught on YouTube video.
The NFL has stepped up security at stadiums because of fights and shootings outside games.
The Associated Press Contributed to this Report