The 13 Welsh players based in England and France initially named in Tandy’s autumn squad are not available for Wales this weekend.
Lock Adam Beard is based in France, while there are 12 players who ply their trade in England with Rhys Carre, Olly Cracknell, Archie Griffin, Nicky Smith, Dafydd Jenkins, Freddie Thomas, Tomos Williams, Jarrod Evans, Louie Hennessey, Max Llewellyn, Nick Tompkins and Louis Rees-Zammit unavailable.
In contrast, Wales have a long-term deal with their own sides to release players for the national side, so Ospreys, Cardiff, Scarlets and Dragons names make up the 30-strong squad this weekend.
The Springboks will also have a limited selection because some of their players have returned to English, French and Japanese clubs, while head coach Rassie Erasmus has also released players back to South African sides for URC action.
South Africa will be without world player of the year Malcolm Marx, Thomas du Toit, Boan Venter, Lood de Jager, RG Snyman, Pieter-Steph du Toit, Grant Williams, Handre Pollard, Manie Libbok, Jesse Kriel, Cheslin Kolbe and Edwill van der Merwe, who have returned to their provincial unions and clubs.