Cape Town - Springbok coach Rassie Erasmus says a decision will be taken next week over possible replacements for the injured Frans Steyn and Bismarck du Plessis.
Both players were on Wednesday ruled out of South Africa's three-Test series against England with what Erasmus described as "niggles" on Thursday.
That came after Montpellier conducted their own medical examination of the players following Saturday's French Top14 final against Castres.
While Du Plessis and Steyn were not going to feature in the first Test anyway, their unavailability for the rest of the series is a massive blow to the Boks, particularly at hooker where South Africa find themselves without first-choice Malcolm Marx.
The crisis at No 2 means that Erasmus has had to turn to Bongi Mbonambi for Saturday's first Test against England in Johannesburg, despite the Stormers man having played less than 40 minutes of Super Rugby all year.
Addressing media on Thursday, Erasmus confirmed that a decision on whether to call on reinforcements would only be taken after the first Test.
Du Plessis and Steyn would, however, still be part of the Bok plans moving forward in 2018.
Having named a squad of 43 ahead of last weekend's Test against Wales in Washington, it was always Erasmus' plans to trim that squad down ahead of the second Test in Bloemfontein.
Saturday's first Test between South Africa and England at Ellis Park is scheduled for 17:05.
15 Willie le Roux, 14 Sbu Nkosi, 13 Lukhanyo Am, 12 Damian de Allende, 11 Aphiwe Dyantyi, 10 Handre Pollard, 9 Faf de Klerk, 8 Duane Vermeulen, 7 Jean-Luc du Preez, 6 Siya Kolisi (captain), 5 Franco Mostert, 4 RG Snyman, 3 Trevor Nyakane/Wilco Louw, 2 Bongi Mbonambi, 1 Tendai Mtawarira
Substitutes: 16 Akker van der Merwe, 17 Steven Kitshoff, 18 Wilco Louw/Thomas du Toit, 19 Pieter-Steph du Toit, 20 Sikhumbuzo Notshe, 21 Ivan van Zyl, 22 Elton Jantjies, 23 Warrick Gelant
15 Elliot Daly, 14 Jonny May, 13 Henry Slade, 12 Owen Farrell (captain), 11 Mike Brown, 10 George Ford, 9 Ben Youngs, 8 Billy Vunipola, 7 Tom Curry, 6 Chris Robshaw, 5 Nick Isiekwe, 4 Maro Itoje, 3 Kyle Sinckler, 2 Jamie George, 1 Mako Vunipola
Substitutes: 16 Luke Cowan-Dickie, 17 Joe Marler, 18 Harry Williams, 19 Brad Shields, 20 Nathan Hughes, 21 Ben Spencer, 22 Piers Francis, 23 Denny Solomona