Former Mississippi State Bulldogs head coach Zach Arnett reacts after a failed series of down against the Auburn Tigers during the second half at Jordan-Hare Stadium. John David Mercer-Imagn Images

Zach Arnett Resigns As UNLV Defensive Coordinator

Originally posted on UNLV Rebels on SI
By Mark Morales-Smith | Last updated Apr 8, 2025 9:22 AM ET

On Monday, UNLV Rebels football coach Dan Mullen unexpectedly announced that the team's defensive coordinator and linebackers coach, Zach Arnett, has resigned from the program for personal reasons. Arnett was a former Mississippi State Bulldogs coach who Mullen had tabbed to run his defense in his first year with the program. The Rebels are set to participate in their sixth spring practice on Tuesday. Associate head coach Paul Guenther will take on the defensive coordinator duties on an interim basis.

Recently hired UNLV DC/LB coach Zach Arnett has resigned for personal reasons. Arnett was previously coach at Mississippi State. UNLV associate head coach Paul Guenther will assume duties of defensive coordinator on interim basis
— Brett McMurphy (@Brett_McMurphy) April 7, 2025

Guenther is a former teammate of Mullen's from their days at Ursinus and went on to coach the program from 1997 to 2000. However, he has spent most of his coaching career in the NFL. He has served as the defensive coordinator for both the Cincinnati Bengals and Las Vegas Raiders from 2014 to 2020, while spending last season as the defensive run game coordinator.

The team will have to adjust on the fly with spring practice in full swing. It's unclear how much of the current system that Arnett had already been implementing will remain in the game plan moving forward. It will likely depend on who the program hires to be the defensive coordinator moving forward if they don't decide to just stick with Guenther for at least the remainder of the 2025 season.

The Rebels kick off their season on August 30 against the Sam Houston Bearkats, giving them just under five months to get their defense situated. Mullen and his staff will look to build off of the success that Barry Odom brought to the program before moving on and taking over the Purdue Boilermakers job this offseason. With Boise State leaving the Mountain West Conference in 2026, Mullen is poised to bring his SEC experience to UNLV and build them into a Mountain West powerhouse in the new-look conference.

This article first appeared on UNLV Rebels on SI and was syndicated with permission.

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