'Instinct' tells All Blacks it is Mo'unga's time

Richie Mo'unga is riding high after a stellar season for Super Rugby champions Canterbury Crusaders

Instinct told coach Steve Hansen the time was right to put Richie Mo'unga in the driver's seat as the All Blacks brace for a powerful forward battle against Argentina in Nelson on Saturday.

The All Blacks were giving nothing away on Thursday about how they will meet the challenge -- either confronting Argentina head on or moving their pack to the outside channels -- but whatever the plan, Mo'unga will be in charge.

After a stellar Super Rugby season for champions Canterbury Crusaders, the 24-year-old pivot gets his first start in only his second Test, with Hansen saying the time was right to blood him as the starting playmaker.

"You've got to go with your instincts," Hansen said, naming Mo'unga to replace Beauden Barrett in a starting XV with eight changes from their last outing against Australia two weeks ago.

"You get a feel for how the guy is travelling and then say right, let's give it a go," he added of the latest prodigy to emerge from New Zealand's fly-half production line.

"There's no doubting his playing ability."

Argentina have never beaten New Zealand but they go into this Test laden with confidence following their recent 32-19 win over South Africa.

They have a forward pack brimming with muscle, which they showed against the Springboks, and have also developed a smart short-passing game under new coach Mario Ledesma.

And while their skill-set is developing, the set piece remains the foundation stone of the Pumas' game plan.

All Blacks centurion prop Owen Franks described the Pumas scrum as "a big challenge", while lock Brodie Retallick said they have taken the lineout to another level.

"In the past we've backed our speed to get on top of them but seeing them in the first couple of rounds, they've become very explosive and they're chucking their jumpers outrageously high in the air," Retallick said.

Among the multiple changes in the All Blacks, Scott Barrett will partner Retallick at lock with Sam Whitelock as a lineout insurance policy on the bench.

Although Sam Cane was fit to play, Hansen opted to leave him out of Matchday 23 with Ardie Savea, the starting number seven, the only specialist openside flanker.

Luke Whitelock, on the bench, will cover the openside if necessary, suggesting the All Blacks have prepared for a more defensive final-quarter than usual.

Hansen rated Argentina "a challenging side", saying he had allowed for all possibilities.

"They're big, they're good at the set piece and they've started to grow their running game, as you can see they've got plenty of pace," he said.