All Blacks coach Steve Hansen has admitted his tactic of starting both Beauden Barrett and Richie Mo'unga is a plan that's been a "quite a while" in the making.
Barrett will shift to fullback - the position where he began his All Blacks career - for Saturday's Rugby Championship test against the Springboks, allowing Mo'unga to slide into the number 10 jersey.
With the World Cup fast-approaching, Hansen said the timing was right to test drive the new pairing in a starting capacity.
"It's probably time," said Hansen. "We've got a plan with a whole lot of things we want to do before we get to the nitty-gritty business and we felt Saturday's game was the right time to try that part of the plan."
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"Richie's been playing very well for the last couple of years. At some point, you want all your good players on the park. Both of them are world-class.
"You've got two ballplayers on the park and you've got two world-class players on the park."
He revealed the conversation he had with Barrett to advise the two-time World Rugby player of the year of his new position was a quick one.
"I didn't ask his opinion. I know he can play fullback and he knows it too. I said 'you're playing fullback' and he said 'no worries'. That's about how it went."
Hansen is still unsure which player would claim kicking duties, though Barrett had the superior percentage success rate of the two through Super Rugby.
The adjustment is one of a string of changes to the side that edged Argentina 20-16 in Buenos Aires last weekend, that includes the conspicuous absence of loose forward stars Sam Cane and Ardie Savea.
Captain Kieran Read will be the only established player in the starting loose forward spots, with Shannon Frizzell and Matt Todd making rare run-on appearances.
Speculation is mounting regarding a potential shift of Read to blindside flanker, which would allow both Cane and Savea to make their considerable presences felt as part of the starting pack.
Hansen kept his cards close to his chest when pressed on the issue.
"You'll have to wait and see. There's no point in me telling the world what we're doing," Hansen said. "They can find out. It's a good question, but I can't answer it."
One player under the microscope will be Sonny Bill Williams, and Hansen was clear regarding what he wanted out of the oft-injured star, who barely featured for the Blues during Super Rugby after undergoing knee surgery.
"We've got to see him stay on the park. If he comes off it's because he's run out of energy as opposed to injury."
"We know he can play rugby at a high level, so it's his durability at the moment that's been affecting him getting on the park. We just want to see him put some minutes together and we'll assess it from there."
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