SPOKANE, Wash. — Washington State defensive tackle Andy Roof was kicked out of school, four months after being arrested for allegedly head-butting a man at a party.

The Cougars also announced that senior offensive lineman Dan Rowlands has been forced to quit the team due to chronic shoulder pain.

Roof is being investigated for assault, stemming from a campus brawl, but has not been charged.

He missed last season after he was suspended from school for alcohol offenses. He wasn't expected to start, but he figured to get substantial playing time this season.

Coach Paul Wulff said the student conduct board decided to dismiss Roof, a 6-foot-9, 299-pound senior from Spokane.

"I was very disappointed when I heard the decision," Wulff said in a statement released by the school. "Since I arrived on campus, Andy has been a great leader for this program on the field, in the locker room, in the classroom and done everything we ask of all student-athletes."

Roof played as a freshman and became a starter his sophomore year. He had been expected to see plenty of action this season. He told reporters earlier this year that he had stopped drinking after being kicked out of school last season.

Rowlands made 21 starts in his career for the Cougars, including all 12 games last season at right guard.

Washington State opens the season against Oklahoma State on Saturday in Seattle. The Cougars travel to play Nov. 29.