In 1979, Eddy joined the Hamilton Tiger-Cats coaching staff, where he was reunited with his former boss in Saskatchewan, John Payne.

[4] Eddy was the defensive coordinator of the Houston Gamblers for both of the team's seasons in the United States Football League (USFL).

He spent three seasons there, helping the school post a 22-11-1 record, while leading the Southwest Conference in defense in 1988 and 1989.

The Oilers earned three playoff berths, including the club's first AFC Central Division crown in 1991.

He was fired following the Oilers 1992 playoff loss to the Buffalo Bills in an infamous game which would become known as The Comeback, when the team lost 38–41, after being in front 35–3, early in the third quarter.

In 2000, he was one of the candidates for the vacant Cowboys head coaching position, but lost the job to Dave Campo.