New Zealand not taking any risks over captain Richie McCaw

McCaw will miss his team's final Pool C game against Tonga in Newcastle on Friday after suffering a bang on his thigh during last week's victory over Georgia.

"If we were playing a final, he would be fine, but we are just not prepared to take any risks with anyone that is not 100 per cent," Hansen said.

"He got a bang on his thigh and it's just really sore when he stretches out at top-medium pace, so it is just not worth risking it.

"We've had plenty of gasps from home before, but we're okay with it and the people that are anxious about it don't need to be anxious. If this was the quarter-final, he would be playing."

"We've got enough depth to be able to say, 'hey, we don't have to risk people if they're not 100 per cent'."

Number eight Kieran Read takes over leadership duties in McCaw's absence, while centre Ma'a Nonu will become the sixth All Black to win 100 Test caps after McCaw, Keven Mealamu, Tony Woodcock, Dan Carter and Mils Muliaina.

Reflecting on Nonu's achievement, Hansen added: "The first conversation I ever had with him was that we don't think you're fit enough and we want you to go to sevens. He went there and changed himself.

"He went from being a blockbusting, hard-running centre to a really fit centre who could then play for long periods into the game. He's developed the skills over the period and is a beautiful passing centre as well as a blockbusting runner.

"He has grown into a leader within the group. He doesn't say a lot, but when he does speak it's right on the money. He asks a lot of himself and cares a lot about the team - and we care a lot about him.

"It's a fantastic achievement to play one Test for the All Blacks let alone 100, and he should be very proud of himself."