didulica started to play football in the north geelong warriors. in 1996, he moved to the melbourne knights, a club whose team primarily consists of australian croats, and played for them until 1999. then he transferred to ajax amsterdam, whence he was first loaned to belgian side germinal beerschot for a couple of months in 2001 before eventually moving to austria vienna in 2003. after spending three seasons as a regular in goal for austria wien, didulica returned to the netherlands and was signed by az alkmaar. he made seven eredivisie appearances with the club before being forced to take a longer break following a brain concussion he sustained in a league match against psv eindhoven in october 2006 after being hit with the ball in his head from a shot by psv's australian international jason čulina.