Career
He signed professional terms in February 1976 and made his senior debut on 31 August 1976, in an away 1–3 defeat to Watford in the League Cup. His first Football League appearance was on 2 March 1977, in an away 2–3 defeat to Lincoln City, when he scored one of Palace"s goals. Brennan made only one further appearance that season and one in 1977–1978 before signing for Plymouth Argyle on 1 August 1978.
At Plymouth, Brennan made only six appearances and moved into non-league football with Leatherhead in 1979.
Brennan died on 13 August 2015, aged 56.