In 1986 with the help of Iona's coach Harold Crocker, Donahue got a tryout with the New York Jets NFL Football team. He signed a free agent contract with the New York Jets to play nose tackle. He participated in mini-camp and summer training camp with the Jets. He was released in August 1986. In 1987, Donahue signed a free agent contract with the Green Back Packers to play nose tackle. During camp Donahue suffered a knee injury. He was released in August 1987. In 1989, he joined the Toronto Argonauts of the C.F.L. Donahue hurt his knee while with the Argonauts. He was released from his contract that same year.
After his football days were over he embarked on a professional wrestling career. He was known most notably as the "Dublin Destroyer" and Brian "The Basher." Donahue wrestled with Universal Wrestling Federation (UWF) in 1991 and then with the World Wrestling Federation (WWF) during 1991-1992. While training with former professional wrestler Mark Tendler, Tendler introduced Donahue to an acting agent. It was during this time that he began to fully pursue acting with full heart. Working his way up the ranks, taking classes, auditioning, and landing commercials, some TV roles, and eventually small roles in films.