Oklahoma’s Joe Castiglione is preparing to end the longest current tenure for an athletic director in major college sports, ESPN reported.Castiglione, who has guided the Sooners’ sports operations since 1998, will retire from his full-time role during the upcoming school year, per the report.Castiglione, 67, plans to stay on as athletic director emeritus following the hiring of his successor.Oklahoma has captured 26 national championships and 117 league titles during his 27 years in Norman, which included the transition from the Big 12 to the Southeastern Conference.Castiglione was named the athletic director of the year by Sports Business Journal in 2009 and shared the award in 2018. The National Association of Collegiate Directors of Athletics named him its top AD in 2000 and 2018.