George Bell has been ruled out of the All Blacks' tour of South Africa after suffering a calf strain in training on Sunday, with the injury expected to keep him sidelined for six to eight weeks.

Uncapped hooker Bradley Slater has been called up as Bell's replacement and will arrive in Cape Town on Wednesday, making him unlikely to feature against the Stormers on Friday — the All Blacks' opening tour match.

"We are all gutted for George, to be ruled out of the tour so early," coach Dave Rennie said. "He's had a frustrating past few months with injury so it's a real blow for him to have injured his calf again."

Rennie retains three other hookers in the squad — Codie Taylor, Samisoni Taukei'aho and Asafo Aumua — ahead of a tour that includes matches against the Stormers, Sharks, Bulls and Lions as well as four Tests against the Springboks.