Career
After playing he became coach of Wakefield Trinity from 1996 to 1997. A stylish three-quarter with a great turn of pace, Mitch Brennan trialed with the Canadian Football League side the Toronto Argonauts in 1975 and was offered a contract before visa restrictions prevented his Canadian football career. He returned to Australia and was graded with Brisbane Souths.
Saint George Dragons
His NSWRL career began controversially when in the 1977 pre-season, he was coaxed by his former coach Harry Bath to play for Street George in a trial match at Grafton.
Brennan played under the pseudonym "Mickey Lane" because he was still in contract negotiations with Brisbane Souths. He was recognised and fined $500.
He joined Street George in 1978. Souths and Canberra
Brennan switched to the South Sydney Rabbitohs in 1981 and played 41 first grade matches over two seasons.
He returned to Queensland in 1983 and played with the Redcliffe Dolphins and captaining them until 1985.
In 1986 Brennan returned to the NSWRL with the Canberra Raiders. His three seasons there up till retirement in 1988 were significantly interrupted by injury and he made only 8 first grade appearances.for Canberra. He made his State of Origin debut for Queensland in the sole game played under Origin criteria in 1981.
He appeared in games I and III of 1982 at centre and full-back respectively and in game III of 1983 on the wing.
He scored three tries in his four Origin appearances.