Australia's Paul Gallen insists there is no way he or his national teammates can afford to ease off during rugby league's World Cup despite suggestions a Kangaroos' triumph is cast in stone.

The ease of Australia's 30-6 win over New Zealand, the side considered the Kangaroos' biggest threat, last Sunday night has critics predicting the rest of the tournament will be one-sided.

England are considered by many as the only other side capable of pushing the favourites, but another Australian win this Sunday night could provide a headache for marketers given the semi-finals are not played until mid-November.

Gallen did the right thing by promoters by predicting a close battle at Telstra Dome, and said his club and national coach Ricky Stuart had reinforced the need not to relax in any games.

"If we have an off day anyone could beat us I suppose," Gallen said.

"That's what `Sticky' has drummed into us, not to have an off day and to keep our heads very mentally strong and go out there and individually try to play your best game.

"Hopefully as a team things will come together too."

One of the major reasons behind Gallen's determination to keep his standards high was his fear at losing his spot, given the depth of the Kangaroos squad.

The Cronulla skipper made his Test debut this year, his eighth season in first grade, and rated an international against England a special moment in his career.

"I work very hard to keep my spot," he said.

"This will be my third Test, so if I have an off day there's seven blokes on the sideline there ready to come in and take my spot.

"So I have to try to play, individually, my best game every game to keep my spot and that's what I'm trying to do."

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