NEW YORK -- Columbia coach Pete Mangurian resigned Friday after a winless season and amid reports about a letter that accused him of abusive coaching tactics.

Mangurian was 3-27 in three seasons at the Ivy League school, and the university had previously hired a consultant to review the program.

His departure came a day after the Columbia student newspaper reported that a letter from players was given to the university accusing the coach of verbal and physical abuse and trying to force players to play with concussions.

The letter was later retracted. But the university acknowledged the letter and that it investigated whether injured players were mishandled and "found no evidence to support an allegation of a departure from that protocol with our football players."

The letter was not released by the university and it was unclear whether Mangurian's resignation was related to the allegations.

John Keefe, a senior wide receiver, told The Wall Street Journal he asked for his name to be removed from the letter after "miscommunication" with other players.

"Regardless of how I feel about the program and the coaching staff, I am trying to keep my distance," he said.

Team doctor William N. Levine, an orthopedist, told The New York Times that he could not comment on specific allegations, but said Mangurian never had any say about what the medical staff did when it came to treating injured players.

"In my 16 years at Columbia, no coach, including coach Mangurian, has ever made me have to in any way bend my ethics about taking care of our student-athletes," Levine told the Times.

Columbia has traditionally been one of the least successful programs in Division I and perennially at the bottom of the Ivy League standings. The Lions haven't had a winning season since 1996 and have not had a coach leave the school with a winning record since 1929.