Whitelock, a World Cup winner in 2011 and 2015, was named in the second row with longtime partner Brodie Retallick in a much-changed side tasked with getting the All Blacks back to winning ways after successive losses to South Africa and France.
"He has been a warrior for this team for a long time and to equal someone like Richie is a massive achievement," Foster said on Wednesday of the 34-year-old lock, who made his test debut in 2010.
"We all know how much it means for him to pull on a black jersey and (it will be) a very special occasion, one that we have to make sure we put a performance on that gives that record a lot of respect."
Ardie Savea will captain the side for the second Pool A match on Saturday morning (NZ time) in the absence of Sam Cane, who withdrew before last week's tournament opening loss to France with a back problem and is being managed back to fitness.
Injuries also ruled out centre Jordie Barrett, flanker Shannon Frizell and prop Tyrel Lomax, while loose forward Ethan Blackadder only recently arrived in France as a replacement for winger Emoni Narawa.
"We had to adapt (our plan) based on injuries and who is coming back but we are pretty satisfied that we have a team to rebound from round one," Foster said.
"We just want him to run the game how we want to play it and I'm sure he will," Foster said of the livewire McKenzie.
"He's keen and he's very clear about what we want to achieve."
David Havili will combine with Anton Lienert-Brown in midfield, while power runners Leicester Fainga'anuku and Caleb Clarke get their chance on the wings.
The All Blacks thrashed Namibia 71-9 at the last World Cup - and nothing less than another big win in Toulouse will settle the nerves of the notoriously skittish All Blacks fans.
"It doesn't really matter who you put out in the 23, the black jersey we're blessed to wear demands everything," Fainga'anuku said.
"We want to win games to get ourselves a playoff spot and give us the best shot of winning this World Cup."
Namibia excited for clash
Namibia have made four changes to their team to face New Zealand in a daunting, where they come up against an All Blacks side desperate to bounce back.
Fullback Cliven Loubser, prop Jason Benade, flanker Prince Gaoseb and centre Le Roux Malan all come into the starting team.
Namibia were beaten 52-8 in their opener against Italy, but the score only ballooned out in the closing stages and for much of the match they were in the contest.
The task will be significantly harder on Saturday, though coach Allister Coetzee, who coached South Africa to four successive defeats against New Zealand in 2016 and 2017, has resisted making wholesale changes.
"We knew it was a tough pool," Coetzee told reporters. "It is not scary, we really get excited about it. New Zealand are taking this game seriously.
"It is good for the competition. It is a great opportunity for our players and we are excited to play against them."
Benade comes into the front row to replace Desiderius Sethie, while Gaoseb is in for Johan Retief, who moves to lock in place of Adriaan Ludick. Malan takes over from Danco Burger in the number 12 jersey.
Loubser will be fullback as Divan Rossouw moves to the wing to replace JC Greyling.
Former Australia international Richard Hardwick gets another start at number eight having impressed against Italy, where he beat the most defenders (8) and had the second-most carries (16) for Namibia.
"Comparing our team to last week’s, there are guys coming in and they can make a difference," Coetzee said. "New Zealand is a top nation. Our plan is to stop the momentum and break their rhythm."
Namibia are still seeking their first win at a World Cup having lost all 23 games played since their debut in 1999.
It would be the biggest shock in rugby history were they to break their duck this week.
All Blacks v Namibia
Stadium de Toulouse
Kick off : 7am on Saturday (NZ time)
New Zealand: 15-Beauden Barrett, 14-Caleb Clarke, 13-Anton Lienert-Brown, 12-David Havili, 11-Leicester Fainga'anuku, 10-Damian McKenzie, 9-Cam Roigard, 8-Ardie Savea (captain), 7-Dalton Papali'i, 6-Luke Jacobson, 5-Sam Whitelock, 4-Brodie Retallick, 3-Nepo Laulala, 2-Samisoni Taukei'aho, 1-Ofa Tu’ungafasi
Replacements: 16-Dane Coles, 17-Ethan de Groot, 18-Fletcher Newell, 19-Scott Barrett, 20-Tupou Vaa'i, 21-Aaron Smith, 22-Richie Mo'unga, 23-Rieko Ioane
Namibia: 15-Cliven Loubser, 14-Gerswin Mouton, 13-Johan Deysel (capt.), 12-Le Roux Malan, 11-Divan Rossouw, 10-Tiaan Swanepoel, 9-Damian Stevens, 8-Richard Hardwick, 7-Prince Gaoseb, 6-Wian Conradie, 5-Tjiuee Uanivi, 4-Johan Retief, 3-Aranos Coetzee, 2-Torsten van Jaarsveld, 1-Jason Benade.
Replacements: 16-Louis van der Westhuizen, 17-Desiderius Sethie, 18-Haitembu Shikufa, 19-Pieter-Jan van Lil, 20-Adriaan Booysen, 21-Max Katjijeko, 22-Jacques Theron, 23-JC Greyling.
