Bath Rugby's Horacio Agulla and Francois Louw will both be in Rugby Championship action this weekend, having been selected by Argentina and South Africa respectively.
Agulla starts on the wing for Los Pumas when they take on New Zealand on Friday, in a side that sees three players make their Rugby Championship debuts.
Number eight Facundo Isa, lock Guido Petti and wing Santiago Cordero have all been named by Coach Daniel Hourcade in his starting XV.
"It's a team built around our previous thoughts. In other words, taking into consideration players who need a rest or are still not 100 percent because of their participation in the European season," commented Hourcade.
"That gives us a chance to give some younger players a run-out before the World Cup. They've earned their place on the pitch."
Flanker Louw takes his place in the back-row to face Australia, with Schalk Burger returning at number eight – one of five changes from the side that took on the World XV last week.
Springbok coach Heyneke Meyer said the changes were all part of the plan to rotate players in the build-up to the Rugby World Cup.
"I've said last week that we will make changes, but it's also important to keep some form of momentum. Saturday's match is going to be massive in the context of our season and we have to ensure we tick the right boxes.
"We played some brilliant rugby last weekend against the World XV in Cape Town and the challenge this weekend is to build on that and improve in the areas we lacked.
"Our basics have to be spot on and it will also be a great test for our defensive systems against a Wallaby side that can rip any team to shreds with the ball in hand."
Argentina: 15 Joaquin Tuculet, 14 Horacio Agulla, 13 Marcelo Bosch, 12 Jeronimo De la Fuente, 11 Santiago Cordero, 10 Nicolas Sanchez, 9 Tomas Cubelli, 8 Facundo Isa, 7 Juan Martin Fernandez Lobbe, 6 Juan Manuel Leguizamon, 5 Guido Petti, 4 Manuel Carizza, 3 Ramiro Herrera, 2 Agustin Creevy (c), 1 Marcos Ayerza.
Replacements: 16 Julian Montoya, 17 Lucas Noguera, 18 Nahuel Chaparro Tetaz, 19 Benjamin Macome, 20 Javier Ortega Desio, 21 Martin Landajo, 22 Santiago Gonzalez Iglesias, 23 Lucas Gonzalez Amorosino
South Africa: 15 Willie le Roux, 14 JP Pietersen, 13 Jesse Kriel, 12 Damian de Allende, 11 Bryan Habana, 10 Handré Pollard, 9 Ruan Pienaar, 8 Schalk Burger, 7 Marcell Coetzee,6 Francois Louw, 5 Victor Matfield (c), 4 Eben Etzebeth, 3 Jannie du Plessis, 2 Bismarck du Plessis, 1 Tendai Mtawarira.
Replacements: 16 Adriaan Strauss, 17 Heinke van der Merwe, 18 Frans Malherbe, 19 Lodewyk de Jager, 20 Teboho Mohoje, 21 Cobus Reinach, 22 Pat Lambie, 23 Lwazi Mvovo.