Having started his career as an Under-9 at Leyton Orient, Martin Brennan progressed through the youth ranks at Spurs, but failed to make the break-through into the first team squad.
Joined Spurs as a 13 year old and was on schoolboy for two years and then two years as a YTS, but finding his way to the first team blocked by more experienced and big money signings, Martin left to join Charlton Athletic, where he played in the Academy and Reserves, but had to go to Cambridge United to get first team football. Stayed at the Abbey Stadium for Two years, but then moved on to play for non-league Welling and Stevenage Borough, before ending his time on the pitch with Dagenham & Redbridge.
Leaving the playing side of the game, Martin joined Leyton Orient as their Academy coach, then returned to Tottenham as the goalkeeping coach for the Academy and Reserves for two and a half years before moving to Adams Park in Nov 2008.
Martin Brennan joined Wycombe Wanderers as goalkeeping coach under the management of Peter Taylor.