Australia's bold move to sacrifice experience for form in Sunday's official World Cup opener against New Zealand already has the camps at odds over whether the Kangaroos will see a debutants' ball or their debutants fall.

Kangaroos coach Ricky Stuart yesterday named four players to make their debuts in the encounter at the Sydney Football Stadium, including two - Glenn Stewart and Anthony Laffranchi - in the back row, a potential Achilles heel that was immediately pinpointed by the Kiwis.

Tawera Nikau, the former New Zealand forward who addressed the squad last week before the 10-team tournament, said the Kangaroos were vulnerable because of their international inexperience in the back row - the other member, Paul Gallen, has played just one Test.

"I think so," Nikau said. "[Coach] Stephen Kearney's pretty smart and obviously so is [assistant coach] Wayne Bennett. They've both been around for a while, and Steve's played in the back row. I think they are a bit vulnerable there. They've got some old campaigners in the front row but when things get a little bit tough, you look to those forwards. Maybe experience will be the difference."

Nikau labelled the Kiwis line-up, also named yesterday and which included only one rookie - Melbourne's Sika Manu - as "one of the most impressive teams in quite a while", and said the squad had the potential to create a "new era" for New Zealand.

Stuart ignored the experience of Craig Fitzgibbon in favour of the exuberance of Laffranchi, Stewart and Josh Perry, while Canberra's Joel Monaghan was preferred to another rookie, David Williams, on the wing. Perry, Manly's grand final-winning prop, conceded the newcomers expected the Kiwis to attempt to unsettle them.

"I'm sure they'll have a crack at whatever they can do," Perry said. "They'll be doing whatever they can do to win the game. We'll be prepared for all that sort of stuff."

Laffranchi, the Gold Coast back-rower, added: "You've got to be a debutant some time. There's no better chance to be in the first game of the World Cup in the centenary year. I'm sure I'll rise to the challenge, and I'm sure the other three will as well."

Far from trying to shield the rookies, Australian selector Bob McCarthy, a former Test back-rower, expected one of them to play a pivotal role in the side. McCarthy said Stewart's selection suggested Stuart wanted to play an "expansive game", and the Manly forward's wide running would be crucial to the Kangaroos' game plan. Stewart was the only Manly player selected in the starting side and one of three named in the squad, something that "shocked" Nikau, the former Melbourne premiership winner.

Stewart has formed a lethal combination with his brother Brett in the NRL. After the withdrawal of the fullback due to a shoulder injury, he is expected to form a similar alliance with the player who shares his younger brother's initials, Billy Slater.

"He [Stewart] has got a good running game, and he'll be running on the edges," McCarthy said. "He's got a good step on him, and I'm pretty sure Billy Slater can read him if he makes a half break and slips a ball. Hopefully, he can read him like his brother. We wanted to play him a bit wider because we haven't got [Ryan] Hoffman.

"Hopefully, we'll make a bit of progress there, and the backs can set the world alight."

Asked about the relative inexperience in the back row, McCarthy said: "They're all in good form, that's the main thing. They've got a bit of inexperience and they'll be a bit nervous, but who have they [New Zealand] picked? They haven't done much either. And I'm pretty sure the front-row experience there will settle those young blokes down."

The other advantage the Kiwis appear to have is match fitness. They have had two warm-up matches, while the closest the Australians have come to match conditions was an opposed session yesterday at Kogarah against the indigenous side that will contest the curtain-raiser on Sunday.

But Laffranchi countered: "We had a big couple of days early on, and everyone seems to be on the money with their fitness - our preparation's been pretty good."

The teams: Australia v NZ

Rugby League World Cup at the SFS on Sunday, 8pm:

New Zealand: Hohaia; Perrett, Matai, Ropati, Vatuvei; Marshall, Leuluai; Cayless (c), Fien, Blair, Mannering, Manu, Smith. Interchange: Halatau, Eastwood, Sa, Rapira.

Australia: Slater; Monaghan, Inglis, Folau, Tate; Lockyer (c), Thurston; Civoniceva, Smith, Price, G Stewart, Laffranchi, Gallen. Interchange: Kite, Perry, Tupou, Gidley.