 In 2003, Mendenhall accepted the defensive coordinator position at BYU under then head coach Gary Crowton.Crowton resigned at the end of the 2004 season which was his 3rd consecutive losing season.The BYU head coach position was first offered to former Cougar linebacker and then-defensive coordinator at the University of Utah, Kyle Whittingham, which resulted in Mendenhall calling UNLV head coach, Mike Sanford, about the defensive coordinator opening on his staff.