The outcome of Saturday's Rugby Championship Test between New Zealand and Australia may rest in the hands of novice flyhalves Tom Taylor and Matt Toomua and the older but less-favoured men who are their appointed understudies.

Taylor will make an unexpected Test debut for a New Zealand team which has three flyhalves out of commission with injuries, though he isn't even regarded as a specialist No. 10 by his Super Rugby team.

Toomua has been handed a second chance in the No. 10 jersey by Wallabies coach Ewen McKenzie after his sound but unspectacular debut in Australia's 47-29 loss to New Zealand in Sydney last weekend.

If either player falters, they will hand an opportunity to their replacements - Colin Slade for the All Blacks, who will play his first Test since injury wrecked his 2011 World Cup campaign and halted his international career, and to Quade Cooper for Australia, who will renew his role in New Zealand as a pantomime villain. His every entrance and action is met with a chorus of boos.

Hero role

Circumstance then affords all four players the chance to play the role of hero in a match in which New Zealand are expected to extend their long history of dominance over Australia, emphasised last weekend when they became the first Test nation to post 100 wins over another nation.

If they win again, and their complete victory last weekend suggests they will, they will prolong their decade-long hold on the Bledisloe Cup which is contested annually by the All Blacks and Wallabies.

The high hopes that McKenzie will usher in a new era for Australian rugby - improving on the meagre successes of predecessor Robbie Deans - will also have been frustrated.

No coach can be judged on one Test performance but McKenzie's first Test in charge was far from impressive. He promised a return to the attacking style for which Wallabies teams were once famous but his players delivered an error-ridden performance which allowed the All Blacks to win by six tries to two.

"We're renovating a team,'' McKenzie said.

"We had five guys on debut last week, but this is not a three-year project, we haven't got time to be messing around.

"We've got to aim up. We've got good players, and those good players have been rewarded because they've been performing.''

The Wallabies have been reluctant to join in any banter before Saturday's return Test and All Blacks coach Steve Hansen interprets their silence as ominous.

"They're obviously going to be more dangerous,'' Hansen said.

"The first sign of that is they're not talking as much this week.

"If we were in their situation, and we were eight years ago, we would just shut down and get right into it. The mentality would be we've got to go out and prove a point.''

As Hansen suggested, New Zealand were able to win comfortably in Sydney by exploiting Wallabies' errors and defensive lapses of which there was a steady supply. Fullback Jesse Mogg and winger James O'Connor have retained their positions in the Australian starting line-up, though they were guilty of some of the most serious failures in defence.

The Wallabies had enough ball to win last weekend but in pressing for a fast-paced and attacking game with a fairly new backs combination, McKenzie may have asked the Wallabies to run before they could walk.

"A lot of detail gets lost in the scoreline. All we can do is attend to the detail and do something about the scoreline next time we play,'' McKenzie said.

Attention to detail

The All Blacks, also, have to be more attentive to detail. No team in world rugby attacks with more proficiency from turnovers than New Zealand - their players share an instinct to swoop on any morsel in broken play.

But they may need to shore up elements of their game, notably their lineout and their tactical kicking. They will look to Taylor for the steady proficiency he brings to the Crusaders for whom he started 10 Super Rugby matches this season - seven at inside centre and three at fullback.

"I've played 10 most of my life really,'' Taylor said .

"Only the last couple of years I've played a bit of midfield, but that's just been more about being able to get out on the park really.''

Taylor is both the son and nephew of All Blacks and he brings physical solidity to the flyhalf role along with a 90 per cent goalkicking record this season.

Toomua has also been preferred to Cooper because McKenzie has again sought his soundness along with Cooper's impact from the bench. McKenzie justified that policy in naming his team.

"I know this group learned a great deal from last week and will be much better for the experience on Saturday night,'' he said.

"We made a decision to reward players that were in-form and who we believed were capable of executing what we are trying to achieve as a group.''