Sportal.co.nz 11.Sep.2012Getty Images
Smith, 26, has gained seven Test caps in the last three years, most off the bench, but he is now more comfortable in the squad.
"I think experience gives you confidence and an insight into the game," he said.
Smith has played fullback and wing for the Highlanders and Otago but his last two appearances for the All Blacks have been as a centre off the bench against Australia and Argentina.
"You've just got to do your homework during the week on the positions where you might be involved so that you know what your role is," he said.
"I'm covering centre so that's another challenge. I enjoyed the game time I had against Australia and I'm just happy to be involved wherever.
"You're involved with the defensive patterns a lot more at centre and it's quite different to fullback and wing."
Smith said he did not want to make public where he would prefer to play for the All Blacks.
"I'm just happy to bet out there and to try to make the most of the chances that I get."
Smith, who was born and bred in Dunedin and attended Kings High School, said he and the All Blacks were excited at the prospect of playing their first test at the roofed Forsyth Barr Stadium.
"It's going to be awesome for us to play there. I went to a couple of World Cup games there last year and I know what the atmosphere is like. It's a great stadium for running rugby."
But it will not be his first Test in his home town. He played in the All Blacks' 6-14 win over Fiji in the farewell match at Carisbrook last year.
Smith said the Pumas presented a tough physical challenge in Wellington.
"We knew they would be tough and we would have to be patient and look to close the game out towards the end, and that's how it happened.
"The South Africans are always very physical. They challenge you in the air, they put in a lot of contestable kicks and they always have a strong midfield."
The All Blacks can wrap up the inaugural Rugby Championship if they win on Saturday night - they have 12 points and South Africa are next with seven - but Smith is not counting his chickens.
"We're not thinking about that really. First and foremost, it's just a challenge against a team which will be even harder after coming off a loss."