Mississippi State athletic director Zac Selmon, who previously served as the Sooners’ deputy athletic director, has long been rumored to be a strong candidate to replace Castiglione. Texas Tech athletic director Kirby Hocutt worked under Castiglione at OU from 1998-2005 and was college teammates at Kansas State with Brent Venables.

Castiglione is entering his 28th year at Oklahoma, making him the longest-tenured athletic director in major college sports.