[2] Despite winning Bendigo's under-18s' best and fairest player award in 2006, he was overlooked in the AFL national draft.

Generally seen as a running half-back or midfield player, Geary was selected by St Kilda with pick 58 in the 2006 AFL Rookie Draft, a busy rookie draft for the Saints which also saw Clinton Jones, Luke van Rheenen, Robert Eddy, James Wall and Jayden Attard selected.

[5] His career started positively, playing in the pre-season 2008 NAB Cup competition which St Kilda won in the final against Adelaide.

In Round 1, 2008, Geary made his home and away season debut for the Saints, gathering 21 possessions as one of the best-on-ground players against the Sydney Swans.

[6] He played a total of 10 games in 2008, a season which ended at the Preliminary Final stage for the Saints.

Geary was nominated for the AFL Rookie of the Year award, the Rising Star, for his 19-possession game against Essendon in Round 8.

[7] Geary played in 15 of St Kilda's 22 matches in the 2009 home and away rounds, with a 100% record of 15 wins, averaging 16.9 disposals per game.

St Kilda dominated the competition and qualified in first position for the AFL finals series, winning the minor premiership McClelland Trophy.

He had his most productive career match in the final game for the year, the Round 23 match against Fremantle at Docklands Stadium, which was notable as being the final game for Saints legends Justin Koschitzke, Jason Blake and Stephen Milne.