Wallabies captain Stirling Mortlock will shift to the unfamiliar second five-eighth position to cover for the injured Berrick Barnes, and could even be the backup No 10 if injury befalls Matt Giteau at a packed Suncorp Stadium.
Coach Robbie Deans' decision to select a bench of five forwards and two backs, in anticipation of a high-octane encounter, left him with no specialist cover in the playmaker's role and raised eyebrows in Australia this week.
Mortlock trained at first five-eighth today as Deans put the team through their paces at a sun-drenched Ballymore.
All Blacks assistant coach and former test No 10 Wayne Smith admitted it was a risky Wallabies strategy.
"Not sure I would do it. It is a pivotal position but I know Rob well, I've known him for a lot of years and he'll have a backup five-eighth in his mix, there's no doubt about that."
The All Blacks had midfield issues in last year's trans-Tasman test in Melbourne when Luke McAlister was rushed into the unfamiliar No 13 jersey when Leon MacDonald was injured.
Mortlock made the crucial line break through the midfield that led to the Wallabies' matchwinning try.
Smith wasn't prepared to label Mortlock's shift to No 12 as much of a risk, although it cut down the Wallabies' kicking options as both sides look certain to play a safety-first aerial strategy.
"It's not a hell of a difference between 12 and 13, fundamentally most of the skills are the same.
"They've had a kicking option there with Berrick Barnes and I'm not sure Stirling gives them that.
"There are other kicking options in their team. The same thing's been levelled at us with Ma'a (Nonu) but we found other people to kick. I'm sure they'll have a plan.
"Stirling's a great player, along with Richie (McCaw) he's one of the great players in the world at the moment. I guess he'll step up pretty easily there."
Mortlock and Ryan Cross will start a test together for the first time, but Giteau had no concerns about the relatively new combination who square off against Nonu and Conrad Smith.
"It's gone well. This year Stirling's learned to pass so he could play inside centre or outside centre," Giteau said.
"He's been going very well. I think both centres complement each other really well. Stirling's adapted to it quite easily.
"He and Berrick and very different players but Stirling has certainly shown that he's capable of ball playing and I think he enjoys it, he doesn't get beaten up as much."
The All Blacks safely negotiated training today with reserve prop John Afoa (shoulder) still the only injury concern.
A decision on Afoa's fitness will be made tomorrow, with Neemia Tialata ready to step in.
"He's trained well, it's just whether he's up to test match level or not."
The Wallabies had an illness scare with key loose forward Rocky Elsom missing training due to a dose of flu, but team officials insisted he wasn't in doubt.
Smith said the team that played the smartest rugby would win Saturday's test, with the experimental law variations putting more emphasis on kicking game and field position.
"It'll come down to who makes the best decisions on the day and that's not down to one man either, it's down to everyone contributing.
"Both teams understand pretty well what they're trying to do it's just who executes best."
