New Zealand utility back Jordie Barrett insists he is ready to rise to the challenge of being named as the All Blacks' starting standoff to face Namibia on Sunday — despite never having played the position in a test match before.

New Zealand head coach Steve Hansen on Friday announced his team to face the Namibians at Tokyo Stadium, with Barrett taking over from the rested Richie Mo'unga in the No. 10 shirt for the All Blacks' third game of the Rugby World Cup.

The 22-year-old Barrett was one of only three New Zealand players retained from the lineup that beat Canada 63-0 in Oita on Wednesday night, having played that match on the right wing.

Hansen only told Barrett he would be lining up at standoff against Namibia on Friday morning, but the player told reporters later in the day that he was taking it all in his stride.

"I found out I was playing 10 this morning," said Barrett, whose brother Beauden was the All Blacks' regular standoff until Hansen moved him to fullback shortly before the tournament. "I got bounced in and out of positions at training a little bit. Unknown to me, I was going to play 10. But I've been running around various positions in the past few weeks, trying to upskill myself.

"I'm lucky enough to be rooming with my brother and there's little things I've spoken to him about playing 10, and Richie as well," he said. "I've got some awesome players to be able to learn off. I've got some great guys around me to help me out. I'm in good hands."

Hansen also named Brodie Retallick in his team to face Namibia, welcoming the 204-cm second-row forward back to full fitness two weeks ahead of schedule.

Retallick, a World Cup winner in 2015, dislocated his shoulder playing against South Africa in the Rugby Championship in July, and suffered nerve damage that he feared would rule him out of the tournament altogether.

Hansen eventually named Retallick in his squad with the expectation of being able to use him from the quarterfinals onward, but the coach was pleased to be able to give him a run-out earlier than anticipated.

"It's pretty exciting," said Hansen. "He's worked hard and we have great medical staff that have done some great work with him. His rehab work has been outstanding, and Mother Nature, I suppose. He's just a good healer, and let's just hope he stays healed.

"He's come back from injuries and also personal tragedies in the past, so he knows how to go about doing that," he said. "There's no doubting his work ethic. You can see it on the park when he plays. It's just an extension of that. He loves playing and when you get something taken away from you that you love, it's pretty easy to work hard to get it back."

Hansen said he expects Retallick to play around 30 minutes against Namibia, which has started the tournament with defeats against both Italy and South Africa.

Retallick, meanwhile, is just happy to be playing again, with a further pool-stage appearance potentially still to come against Italy on Oct. 12.

"It was always open about when I would be ready," said Retallick. "Obviously, we wanted to make sure it was in the right spot before going out and playing, without risking it. But to able to get a run this weekend is important. I want to push my case moving forward into the tournament over the next couple of weeks.

"It's been eight or nine weeks since the injury happened, so I'm definitely looking forward to getting back out there," he said. "You can do a lot of running, and we have been, but nothing compares to match fitness. It'll be good to get some game time under the belt."

Retallick will line up in the second row alongside Sam Whitelock, who will captain the All Blacks for the sixth time in the absence of regular skipper Kieran Read, who has been rested for the match.

"It's pretty awesome, pretty excited," said Whitelock. "It's one of those ones where you just have to worry about your own game first, and hopefully everything else will flow from there.

"But it's never just you individually. There's a great crew out there. Brodie's a prime example, and he'll lead in his own way."