Thirty-five-year-old Merle Lee of Newton is free on bond after being charged with aggravated assault.
State Police Sgt. Brian Polite said Lee was initially charged with simple assault. However, 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's family told the New York Post that Mohr, dressed in Jets gear, was walking through the MetLife Stadium parking lot after the Jets' 37-10 victory over the Chiefs when he heard offensive 9/11 taunts.
"Our other brother is a fireman, and my father is retired FDNY, so you can understand why a 9/11 comment would especially irk him," Mohr's sister Anna said. "He was shocked anyone would actually say something like that."
But the Post reported up to seven people jumped Mohr, and cited a police source as saying that at least one was wearing a Chiefs jersey.
Mohr underwent hours of surgery Tuesday at Hackensack University Medical Center to repair a fractured jaw, cheekbone and eye socket. Mohr is out of intensive care.
The Associated Press contributed to this report.