Before he went into the Big House, where more than 113,000 people had gathered on Oct. 9, a police officer ensured his weapons were empty and double-checked that he did not have any ammunition on him, said Diane Brown, a spokeswoman for the university's department of public safety.
A member of the color guard reported the impostor, who was escorted out by police at 4:15 p.m., about 45 minutes after kickoff.
"Unfortunately, he used his uniform and his status to gain unauthorized access to the field," Brown told The Associated Press. "His response was that he really wanted to see the game, he couldn't get a ticket, and he thought he would use his uniform for access."
Brown said the unidentified man was compliant. The Washtenaw County prosecutor's office is looking at the case, but has not decided yet whether to file any charges, she said.
The university is reviewing its protocols at checkpoints to the stadium, but nobody is facing disciplinary measures, she said.
WJBK-TV in Detroit first reported on the security breach.
The unidentified imposter is not the only fan who made headlines related to the Michigan-Michigan State game. Earlier this month, ato install a pacemaker in his chest so he could watch the game.