Boise State says Lawrence was sent home Thursday. He had also been suspended earlier in the year for a home game against UNLV for rule violations.
Lawrence led the Broncos (No. 19 BCS, No. 20 AP) in sacks with 9.5 and had two fumble recoveries this season, his first at Boise State.
He has been replaced in the lineup for Saturday's game against Washington by Tyler Horn.