[13] After starting the 1999–2000 NBL season with a one-game stint with the Wollongong Hawks,[14] Shanahan joined the Cairns Taipans in November 1999 and played 22 games.
[24] After playing for the Stirling Senators of the State Basketball League (SBL) in 2005,[25] Shanahan re-joined the Wildcats for the 2005–06 NBL season.
[1] Shanahan served as player-coach of the Ballarat Miners in the 2007 SEABL season, with the team missing the playoffs.
[34][35] He helped the Suns win the Division 1 state league title in 2012 with grand final MVP honours.
[36][37] He left Coffs Harbour Basketball in December 2012 after three years as operations and development manager.
[40] After sitting out the 2015 season, the Raiders returned in 2016 in the Big V. Darryl McDonald was named men's coach, as Shanahan continued on as Knox Basketball's development manager.