(BCSNN) -- Just five days after firing longtime head coach Mike Gundy, Oklahoma State dismissed defensive coordinator Todd Grantham on Sunday, ending his tenure after just four games. Quality control coach Clint Bowen will take over defensive play-calling duties as the Cowboys continue their Big 12 schedule under interim head coach Doug Meacham.

Grantham’s defense surrendered 612 total yards and 45 points in Saturday’s home loss to Baylor, dropping Oklahoma State to 1–3 on the season and extending its losing streak against FBS opponents to 12 games. The Cowboys rank last in the Big 12 in scoring defense, allowing 35.0 points per game and 7.0 yards per play.

Grantham, hired by Gundy in December 2024, signed a three-year, $4.2 million deal that made him the program’s highest-paid assistant. He previously served as defensive coordinator at Florida, Mississippi State, Georgia, and Louisville, and spent 2024 as the defensive line coach for the New Orleans Saints.

Bowen, 52, brings Big 12 experience from his time as Kansas’s defensive coordinator (2014–2018). He joined Oklahoma State’s staff this offseason as an offensive quality control coach and now steps into a critical role as the Cowboys try to salvage a season that has now lost three in a row - Oregon, Tulsa, and Baylor.

Oklahoma State travels to Arizona in Week 6 before hosting Houston. Athletic director Chad Weiberg has not yet announced a timeline for the full-time coaching search, but confirmed that Meacham will be leading things in the meantime.