TCU defensive end Devonte Fields, named the Big 12 preseason defensive player of the year on Monday, was "separated" from the university while an investigation is conducted into allegations that he threatened a former girlfriend with a gun.

According to a Fort Worth police report, Fields allegedly aimed the gun at Haley Brown and said, "I should blast you" early Sunday. The university announced the separation with Fields on Tuesday while Fort Worth police investigate the domestic incident.

TCU released a statement Tuesday:

"Devonte Fields has been separated from the university pending results of an investigation into the allegations against him," it read. "The university does not tolerate harassment or misconduct by a student. The university discipline process will be implemented, which may result in disciplinary action from the university above and beyond any legal consequences the student might face."

The school later clarified that "separated" means that Fields is required to stay away from the school and the football team until the police investigation is completed.

Brown told police that Fields shouted at her and punched her in the head after knocking out a bedroom window early Sunday. Brown had a cut under an eye and a swollen cheek, according to the report. Fields fled before police arrived at the Fort Worth home where the alleged attacked occurred.

According to USA Today, Sgt. Raymond Bush said Fields is considered a subject in a domestic disturbance and is not under arrest. The woman did not to file charges, saying the couple dated for two years but broke up on June 1.

Fields was suspended at the start of the 2013 season for violating team rules and then suffered a foot injury that required surgery in October. He ended up playing in only three games last year but nonetheless was named to this year's watch list for the Bronko Nagurski Trophy, which is given annually to the nation's top defensive player.

TCU coach Gary Patterson was surprised Monday that Fields was named the conference's preseason defensive POY considering his limited action last season.

"I haven't watched him since you watched him," Patterson said.

As a freshman in 2012, Fields was named the Associated Press Big 12 defensive player of the year after posting 18 1/2 tackles for loss and 10 sacks.