New Zealand are wary of the star quality in the core of the Australia side as the two teams prepare to meet in the World Cup final on Saturday.
Half-backs Johnathan Thurston and Cooper Cronk, hooker Cameron Smith and full-back Billy Slater make up the key unit of the Kangaroos outfit.
Kiwi vice-captain Kieran Foran, 24, said: "Their spine is the best in the world and has been for many years.
"They'll probably finish their careers as greats if not immortals."
The key New Zealand quartet of Foran, Shaun Johnson, Kevin Locke and Issac Luke have been together less than 12 months and Foran believes the key to victory at Old Trafford will be to outshine the Australia stars.
He said: "Our spine is young, we're still learning, but we know that if we are to beat Australia, then our spine has got to be better than theirs."
The Kiwis still have injury concerns over wingers Roger Tuivasa-Sheck [ankle] and Manu Vatuvei [groin], and second-rower Frank Pritchard [hamstring], who all sat out training on Tuesday.
Assistant coach Ivan Cleary says the Kiwis must improve on their patchy performance which got them a last-gasp 20-18 win over England in the semi-finals at Wembley on Saturday.
He said: "The Aussies have got great players in every position. They're as formidable as any opponent you're going to face, so if we don't perform to our best, we've next to no chance."
Australia reached the final with a 64-0 win over Fiji at Old Trafford on Saturday.