Carter is nursing a sore back and was a late withdrawal from the Japan match after failing to come through training. His absence gave Colin Slade a chance to cement his back-up status and silence his critics following a patchy performance against South Africa in the Tri-Nations last month.
Half-back Piri Weepu, who proved himself a more than capable pivot in Super rugby and in brief appearances off the bench for the All Blacks, is also being talked about as a possible stand-in for Carter but Slade is recognised as having the first bite at the cherry.
The 23-year-old, however, would have been disappointed with his performance against Japan, missing three of his first four shots at goal -- one in front of the posts from 30 metres out.
He also had a couple of handling errors and threw an intercept pass to Japan wing Hirotoki Onozawa, who scored his team's only try.
Slade improved as the game went on and was rewarded for some good support play when he finished off another All Blacks line break towards the end of the first half.
In the final quarter of the game, Slade was moved to fullback with Weepu coming on at flyhalf.
Weepu immediately made an impact, putting in a deft kick that was gathered by Sonny Bill Williams, who ran almost 50 metres before feeding Ma'a Nonu for a try.
New Zealand finished 83-7 winners over the Japanese, running in 13 tries.
Carter is no easy man to play back-up to, coming into the tournament with a world record 1,238 points in test rugby, and Slade is still inexperienced at international level.
A confidence player, Slade's head seems to drop a little when things are not going his way.
At the end of the first quarter, following a try to flanker Jerome Kaino, Slade missed a handy conversion and his disappointment was evident.
A minute later he spilled a simple pass from scrumhalf Andy Ellis, opening himself up to scrutiny over his temperament and composure, particularly as the All Blacks coaches look towards the business end of the tournament.
Slade was philosophical about his performance after the game.
"There were some errors in there that perhaps Dan (Carter) wouldn't have made," he conceded. "But I'm still learning, and I'm a young guy."
His team mate from the Highlanders Super rugby franchise, All Blacks flanker Adam Thomson, said Slade would benefit from the Japan game.
"He's better for the experience. He just needs to settle there (flyhalf) and just understand what he needs to do at this level," said Thomson.
"As the game went on he went well and showed some of the skills that he's got.
"He's like anyone. When you come into this level, and there's a lot of pressure, it takes a while to find your feet. Especially at pivot, where you need to run the game. He just needs a little bit of time in the saddle."
Slade will hope he gets more time in the saddle as the All Blacks prepare to face their World Cup nemesis France, possibly without Carter, in Auckland next Saturday.
