New Zealand have revealed that key pair Richie McCaw and Mils Muliaina will be rested for Friday’s World Cup Pool B clash against Japan.

McCaw is struggling with a calf injury and Muliaina has a tight hamstring, so Isaia Toeava and Victor Vito will start.

"It's disappointing to have the players unavailable, especially Richie and Mils who were both looking forward to playing against Japan," coach Graham Henry said.

"But injuries are something that we all have to deal with and it's great that we have versatility in the squad so Isaia is able to slot in at full-back."

Hooker Keven Mealamu will captain the tournament hosts, who are also without Dan Carter and Israel Dagg.