Loosehead prop Ethan de Groot (24) and blindside flanker Shannon Frizell (28) come into the squad at the expense of Karl Tu'inukuafe (29) and Pita Gus Sowakula (27).
Despite media reports to the contrary, openside flanker Sam Cane (30) has retained the captaincy for the championship, which starts for the All Blacks with two tests against the Springboks in South Africa.
Centre Braydon Ennor (25), prop Tyrel Lomax (26) and uncapped lock Josh Dickson (27) will join the squad on the trip to South Africa as cover respectively for Jack Goodhue (27), Angus Ta'avao (32) and Brodie Retallick (31), who are injured or suspended.
Consecutive home losses to Ireland in their July series stunned New Zealand and put huge pressure on Foster, who has now led the All Blacks to only one win in their last five matches.
"There have been some thorough conversations this week, as there always are around our performance environments, and these will continue," said New Zealand Rugby chief Mark Robinson.
"It's exciting to be heading back to South Africa for the first time in several years - we have two big games ahead of us there and our focus now is to support the team to improve performance and be successful."
