He previously served as the defensive line coach for the Baltimore Ravens, Tampa Bay Buccaneers, Cleveland Browns and Detroit Lions.
[7] On February 11, 2021, Cullen was hired by the Jacksonville Jaguars as their defensive coordinator under head coach Urban Meyer.
[9] On February 5, 2022, Cullen was hired by the Kansas City Chiefs as the team's defensive line coach for the 2022 season.
[14] Cullen was fired in 2005, shortly after his hire at the University of Mississippi after being charged with drunk and disorderly conduct after passing out in a local Subway.
[15] Cullen was arrested in 2006 for driving under the influence as the defensive line coach of the Detroit Lions.
[16] He was fined $20,000 and suspended for one game by the NFL for "conduct detrimental to the league" and sentenced by a judge to 10 days of community service and to attend Alcoholics Anonymous meetings.