Evan Cooper, the Nebraska defensive backs coach and passing game coordinator, has resigned from his position for personal reasons, as confirmed by a university spokesperson. Cooper, a longtime associate of head coach Matt Rhule, played a significant role in talent evaluation and recruiting, contributing to Nebraska's strong defensive performance in 2023. His resignation comes just weeks before the start of preseason camp. ESPN reports that John Butler, a seasoned NFL coach with experience at the Houston Texans and Buffalo Bills, is expected to replace Cooper. Butler brings a wealth of experience, having previously served as the defensive backs coach and defensive passing game coordinator for the Bills. Nebraska's defensive unit, under the guidance of coordinator Tony White, is anticipated to remain a strength for the team.