[5] Hayes is part of a tight end lineage at Iowa that had Marv Cook, Dallas Clark, Tony Moeaki, George Kittle, Noah Fant, T. J. Hockenson and Sam LaPorta and others following him in the program.

While coaching in Norman, the 2000 Oklahoma Sooners football team won the BCS National Championship Game.

Hayes joined Marvin Lewis's Cincinnati Bengals staff in 2003 and won 4 AFC North titles on the way to 7 NFL playoff berths.

On April 18, 2019, Hayes was announced as the first head coach and general manager of the St. Louis BattleHawks franchise in the revived XFL.

On June 9, 2022, Dallas Renegades head coach Bob Stoops hired Hayes to serve as his offensive coordinator for the 2023 XFL season.

[12] Hayes's son, Jaxson,[13][14] starred on the 2018–19 Texas Longhorns men's basketball team as a freshman and declared for the 2019 NBA draft.

[15] Hayes's daughter, Jillian, committed as a member of the 2020 recruiting class to play college basketball at the University of Cincinnati.