"This is my chance. I want to make the most of it this Saturday night. Trying to do everything I can to be part of the starting line-up. Do everything I can to stay in the team.
"I've got to go out there and do my core roles to the best of my ability and make sure my preparation is done really well."
Smith had an average test last week against Argentina but was ruled out by team management for other reasons.
"Unfortunately, for Aaron Smith, we have got a strong focus on recovery and he broke a protocol on it last week so that made him ineligible for the first XV," All Black coach Steve Hansen said.
Hansen declined to elaborate on what Smith did, but it is believed the Highlanders halfback was late for a recovery session with the All Blacks in Wellington on Sunday morning.
Hansen said the protocol was "non-negotiable", and the consequence for Smith was that he did not start this week.
"It is like rules in your family. If you break them, there is consequences. That is the way we are living and we make no excuse for them."
Hansen said he could not talk for Smith but he supposed the halfback would be unhappy he has been dropped from the starting XV.
Smith's dumping is a big call from Hansen. The Highlanders halfback looked like the ideal player to take on the big South Africans with his quickness around the breakdown and long passing game.
Under the roof, on a ground where he has played much of his rugby of late, Smith shaped as a key man for the All Blacks.
But rules are rules, and Hansen, along with senior members of his team, is strong on discipline, and the team concept.
Weepu will now have to step up to the plate, but he showed encouraging signs last week.
That game was played in driving wind and rain and there will be none of that come tomorrow night.
Weepu will have to get to the breakdown quickly and find his runners with accuracy.
He has improved from the start of the year but has not played a lot with first five-eighth Aaron Cruden.
Hansen said Andrew Hore was starting at hooker as he was a quality player and it was time for him to step up.
Sam Whitelock has responded well to his dumping last week and will take the place of Brodie Retallick, a young player, who has had a big workload this year.
Ben Smith had been replaced on the bench by Tamati Ellison as Ellison gave more cover at second five-eighth than Smith, Hansen said.
The Springboks will come with the standard physical game and Hansen was expecting nothing but total commitment from the opposition.
" We've got to match that physicality, passion and desperation they have got. They have not had a great start to the championship. If we come in half cocked, we could find ourselves on the back foot. It is all about us being on the front foot and getting things right.
"South Africa will always be the traditional foe. Australia is more like your bigger brother. You always want to be beat your bigger brother but playing South Africa is the ultimate."
