One of the incidents included in the lawsuit involves highly-regarded trainer Jamie Naughright, who according to court documents, reported Manning, then a Tennessee student, to a sexual assault crisis center in 1996 for allegedly placing his bare bottom and genitalia on her while she examined his foot.
"Even if it's 20 years old. Even if he was in college, I still think it resonates, in large part because of the image that he has created for himself," said Brennan, also an ABC News' contributor.
According to court records, Manning denied assaulting Naughright. However, she included the allegations in a 1997 sexual harassment lawsuit against the University of Tennessee, eventually settling with the university and agreeing to leave her job.
The incident resurfaced in 2000, this time from Manning’s point of view, in his book, “Manning: A Father, His Sons and A Football Legacy.” The book was published in Sept. 2000.
Manning described the 1996 incident in the book as a “crude… but harmless” locker-room exchange, with Naughright simply catching him “mooning” a fellow athlete. The book’s account suggests Naughright was eager to sue the school and described her as having a “vulgar mouth.”
Naughright, who did not reply to ABC News, filed a defamation suit against Manning, his father Archie, the book’s ghostwriter, John Underwood, and publisher, Harper Collins.
A motion – obtained by The New York Daily News – contained her version of the facts in the 2003 defamation case. She claims the book casts her in a negative light and that Manning’s characterizations were false and led to her losing her job at Florida Southern College.
ABC News has been efforting comment from Naughright.
Neither Peyton Manning nor the University of Tennessee responded to ABC News' request for comment.