Between 1998 and 2000 Agius played underage football for the South Australian Sport Institute in the SAPL Under 23 division.

Agius in 2001 was selected in the Australian team that played in the 2001 FIFA U-17 World Championship.

In November 2008 A-League expansion team North Queensland Fury enquired as to Agius' availability to which Adelaide City set a transfer fee of A$20,000.

[5] In December 2008 North Queensland Fury unveiled Agius as their latest signing.

[6] After the 2001–02 NSL season Agius decided to try his hand at Australian rules football, a sport he had played as a junior.