Maltby-born Cusack was a student in Birmingham when Long Eaton United and then Alvechurch got him on the footballing ladder. His performances caught the attention of City, who snapped him up in June 1987. The tall striker was used mainly in the reserves but his form for them was enough to see him secure a new contract.
He found it tough to break into the first team, however, with players such as Newell, Cross and Reid ruling the roost at that time. David Pleat came in to take charge of first-team affairs but it didn't alter Cusack's chances, with him being limited mainly to substitute appearances. He only made five Football League starts for the Foxes.
Peterborough United were prepared to give him a chance and Cusack was part of a deal that brought Alan Paris in the other direction. He was Posh's top-scorer in one season and moved north of the border to help Motherwell to the Scottish Cup Final in 1991 before Darlington splashed-out a club record £95,000 for his services. He suffered relegation with Darlington but enjoyed promotion with Fulham in 1997.
He finished his playing career with Swansea City, who he captained, but continued to be involved in football. He became chairman of the PFA and went on to become Swansea's player-manager for a brief spell. A returned to work with the PFA, as financial advisor, followed.