Columbia University football coach Pete Mangurian resigned Friday following allegations that he was verbally abusive toward players and forced them to play through concussions.

“I have accepted Pete Mangurian’s resignation because we have all come to the conclusion that it would be in the best interests of Columbia athletics,” Columbia University president Lee Bollinger said in a statement, according to The Wall Street Journal. 

“So now we will look forward to completing consultant Rick Taylor’s expert review of our football operations that will help us chart a new direction under a new coach,” Bollinger said.

On Thursday the university’s newspaper, Columbia Spectator, revealed a previously withdrawn letter from 25 members of the school’s football team to Bollinger and Columbia’s board of trustees chair that alleged Mangurian forced players to practice while injured.

In the letter, players alleged Mangurian “consistently denied the diagnosis of concussions” and accused players of being “soft” for sitting out. The players also accused their coach of shoving them and grabbing them by their equipment in a “violent manner,” according to The Wall Street Journal.

In a statement to Fox 5, the school denied the allegations saying “Columbia adheres to a strict medical protocol regarding head injuries for all sports teams and our investigation has found no evidence to support an allegation of a departure from that protocol with our football players.”

“The University routinely reviews complaints and concerns raised by students, even those that have been withdrawn. While we don’t generally comment on specific cases under review, it is essential to note that Columbia adheres to a strict medical protocol regarding head injuries for all sports teams, and our investigation has found no evidence to support an allegation of a departure from that protocol with our football players,” the statement said.

“We are part of the Council of Ivy Group Presidents which has taken a leadership role in addressing concussions in college athletics and we place the highest authority on our students’ health and safety.”

The players refused to comment to the school’s newspaper about the allegations.

However, Dr. Gayatri Devi told Fox 5 that if the accusations are true, the players were placed in extreme danger.

“You really should not be playing if you’ve had a concussion,” Devi told the station. “You need time to rest and recuperate.”

A concussion is a type of traumatic brain injury (TBI) that is caused by a bump, blow or jolt to the head, according to the Centers for Disease Control and Prevention (CDC). It can affect a person’s thinking, sensations, language and emotion. It can also cause epilepsy and increase the risk of Alzheimer’s disease, Parkinson’s disease and other brain disorders, according to the CDC.

Repeated TBIs can be catastrophic and even fatal.