"He has been a great servant to New Zealand rugby, he's a world class fullback, he has been a very key member of this side for a very long time and he deserves the honour," coach Graham Henry told reporters after naming his team on Friday.
"My job hasn't changed that much, my job is to direct the team and perhaps starting the game will make that easier," said Slade, who has won nine caps to Carter's 84. "I'm going out there to be myself, I'm not trying to be DC."
Sonny Bill Williams and Cory Jane come into the side on the wings after hamstring injuries ruled out Richard Kahui and Zac Guildford.
Piri Weepu, who provides a back-up place-kicking option for Slade, has won the battle for the scrum-half spot while Henry has restored first-choice centres Ma'a Nonu and Conrad Smith to play the Argentines.
Williams got his first opportunities in rugby union at centre but Henry, perhaps only half joking, said he thought the former rugby league player could even be an option as a flanker.
"He can play on the wing, he can play in the midfield and I think he can play in the loose forwards but this is about making sensible decisions based on his experience so far," said the coach.
"There's a midfield combination which is well-established and is playing particularly well which makes it difficult for him, so he's taken his chances elsewhere."
Argentina finished third at the World Cup and, although the 2011 Puma team has not been of quite the same vintage, Henry said the disappointments of the last five World Cups meant the All Blacks would not take any knockout game lightly.
"We're expecting a big game," he said. "If you don't win, you're dead. There's a huge amount of pressure to perform in finals football, and we know all about that over the years."
Back rower Adam Thomson was originally selected for the team but ruled out through injury, Henry said.
McCaw returns at openside flanker despite the "niggly" foot problem which has seen him pull out of two of their four World Cup matches so far.
"I think Richie's got a challenge on, he hasn't played for a while and he's not preparing as he normally does, so I think it's going to be a mental challenge for him," said Henry.
Muliaina said it was an "honour and privilege" to match his captain's feat by winning a century of caps.
"It's a pretty special achievement ," he said. "I'm just going to get out there and make sure I do my job."
Team - 15-Mils Muliaina, 14-Cory Jane, 13-Conrad Smith, 12-Ma'a Nonu, 11-Sonny Bill Williams, 10-Colin Slade, 9-Piri Weepu, 8-Kieran Read, 7-Richie McCaw (captain), 6-Jerome Kaino, 5-Brad Thorn, 4-Sam Whitelock, 3-Owen Franks, 2-Keven Mealamu, 1-Tony Woodcock