World champions Australia are "expecting the unexpected" against a flamboyant Vodafone Fiji Bati side, promising to play unorthodox sevens-style football in Sunday's World Cup semifinals.

Kangaroos World Cup skipper Darren Lockyer revealed his fears about a Fijian side, he and his teammates know little about.

Lockyer said defensively, they will have to be on their toes and are expecting the unexpected.

Lockyer said Fiji Bati have some talented players who play ad-lib football, and it will be good test for their defence. He said Fiji Bati have come to the game with nothing to lose and will no doubt try a few things by trying to unsettle them and catch them off guard.

The Fiji Bati / Australia semifinal match will kick off on Sunday at 9pm at the Sydney Football Stadium.