Derek Mason is making the move from Auburn to Oklahoma State, where he will replace Jim Knowles as the Cowboys’ defensive coordinator, a source tells The Athletic. Mason, the head coach at Vanderbilt from 2014 through 2020, spent only one season on Bryan Harsin’s staff at Auburn.

Mason emerged as one of the most respected defensive minds in college football in the early 2010s while coordinating defenses at Stanford under David Shaw. He went 27-55 in seven seasons at Vanderbilt but did lead the Commodores to bowl games in 2016 and 2018. In his one year at Auburn, the Tigers ranked fourth in the SEC in yards per play allowed (5.27) and fifth in points allowed (21.8 per game).