Derek Mason spent the 2021 season at Auburn, working under first-year head coach Bryan Harsin as the Tigers’ defensive coordinator.

However, recently, Mason stepped down from that post amid rumors he was interested in the same position at Oklahoma State.

It appears those rumors were legitimate, as ESPN’s Adam Rittenberg tweeted on Wednesday morning that the Cowboys are expected to hire Mason officially by the end of the day:

Oklahoma State lost DC Jim Knowles to Ohio State this offseason, so Mason fills a big-time void on Mike Gundy’s staff.

Mason brings a wealth of experience to Stillwater. Prior to his Auburn stint, Mason was the head coach at Vanderbilt from 2014-20. He was a key defensive assistant at Stanford prior to his time at Vanderbilt.