Texas Tech has made a change at defensive coordinator, as Matt Wallerstedt is out and co-defensive coordinator/outside linebackers coach Mike Smith has been promoted to defensive coordinator. A formal announcement should be made later today. Update: The school announced the move at 3:58 p.m. CT. The school has also announced that quality control assistant Matt Brock has been promoted to inside linebackers coach.

“I have submitted my resignation to Coach Kingsbury effective immediately because I want the best for the Red Raider program, and this will allow them to go in a different direction on defense,” Wallerstedt said in a statement. “I love our players and this school and have only their best interest in my heart and mind. I wish Coach Kingsbury every success this season.”

“We appreciate all Coach Wallerstedt has done at Texas Tech and we wish him the best,” head coach Kliff Kingsbury said.

The move comes following a 49-28 home loss to Arkansas on Saturday in which the Red Raiders surrendered 438 rushing yards and seven touchdowns on 68 carries. The Red Raiders are off to a 2-1 start in head coach Kliff Kingsbury’s second season, and rank 96th nationally in total defense, 127th in rushing, 104th in yards per carry allowed, and 109th in scoring. Texas Tech opened the season with a 42-35 win over Central Arkansas and a 30-26 win over UTEP. Texas Tech ranked 99th in rushing defense and 84th in yards per carry allowed in 2013.

Wallerstedt signed a three-year deal worth $425,000 annually upon joining the staff in 2013. According to Don Williams of the Lubbock Avalanche-Journal, Wallerstedt’s contract calls for a 90 percent buyout value should he be fired without cause. It is unclear whether that would apply in this case. The Red Raiders are off this week, and open Big 12 play a week from Thursday night at Oklahoma State.