All Blacks coach Steve Hansen said he wouldn't compromise on discipline Thursday as he benched scrum-half Aaron Smith for breaking team rules ahead of the tough Test with South Africa.
The hard-nosed coach made clear punishment for the unspecified breach - reported to be missing a curfew after last week's win over Argentina - was not up for discussion.
"There's nothing to elaborate on. He just broke a protocol that's non-negotiable, and the consequence is you don't start in the XV if you break it," Hansen said.
The emergence of the bullet-passing Smith, 24, has been central to the All Blacks' unbeaten run this year. And Hansen views the Springboks, New Zealand's Rugby Championship opponents in Dunedin on Saturday, as the "ultimate" test.
Smith's replacement is 62-Test veteran Piri Weepu, who produced a stirring performance when he came on for the last quarter of last week's 21-5 win against Argentina.
"They are a big side, they are physical and we have to match that physicality and passion and desperation they have got," Hansen said of South Africa.
"They have not a had great start to the championship so if we come in half-cocked, we could find ourselves on the back foot."
New Zealand lead the inaugural Rugby Championship with three wins out of three, while South Africa have had a win, draw and a loss. Australia lie third and Argentina, in their first southern hemisphere Test competition, are last.
Smith's omission is one of four All Blacks changes with lock Sam Whitelock and flanker Liam Messam returning to give added muscle to the forwards, and Andrew Hore starting at hooker.
Although Weepu is not as quick as Smith to clear the ball, he does offer more composure - which could be significant for fly-half Aaron Cruden, who again fills in for the injured Dan Carter.
Springbok coach Heyneke Meyer has also stressed the importance of on-field discipline as he made only two changes to the side that lost 26-19 to Australia last weekend.
Lock Flip van der Merwe replaces the suspended Eben Etzebeth and Francois Louw comes in for Marcell Coetzee to bring more experience marking All Blacks captain Richie McCaw on the openside flank.
Tighthead prop Jannie du Plessis has been provisionally retained despite a hamstring strain. His fitness will be reassessed on Friday.
Meyer said the Springbok were guilty of "two soft moments" against Australia that cost them the game - and he wanted no repeat against the All Blacks.
"There's a huge difference in playing the All Blacks in South Africa than playing them here," he said.
"We don't have a good record against them in New Zealand. If you want to win then you have to be tactically astute, your defence has to be impeccable and there needs to be no soft moments in your discipline."