Leroy McKelvey, 60, appeared in Bergen County Superior Court on Tuesday and pleaded guilty to possession of a stun gun, a fourth-degree offense that typically calls for probation. His sentencing is scheduled for Dec. 7.
McKelvey's case was scheduled to go to trial next month and he was prepared to argue that he acted in self-defense, his lawyer Navarro Gray said.
Witnesses said at the time that fans in McKelvey's section became angry when McKelvey, who was dressed in a Cowboys jersey, refused to stand during the national anthem.
The game was being played at MetLife Stadium on the 10th anniversary of the Sept. 11 attacks.
McKelvey was arrested during the game by New Jersey State Police and charged with eight counts, including aggravated assault, a third-degree offense that carries a 5-to-10 year sentence upon conviction.
A message left with the Bergen County prosecutor's office seeking comment was not immediately returned.