He made four changes to the pack and three in the backline with prop Nahuel Tetaz Chaparro (33) and centre Jeronimo de la Fuente (31) returning after missing the recent trip to New Zealand, where Argentina upset the All Blacks 25-18 in Christchurch but were then thumped 53-3 in Hamilton a week later.
Eduardo Bello (26) also returns in the front row and Matias Alemanno (30) in the second row while Juan Martin Gonzalez (21) come into the line-up of loose forwards.
Tetaz Chaparro had been rested for the trip Down Under and Cheika said there was no better way "to focus him on his return than to throw him in against the Springbok front row”.
Among the backs, De la Fuente has recovered from a hamstring pull while Gonzalo Bertranou (28) replaces Tomas Cubelli at scrum half.
Cheika told a virtual news conference on Thursday he was confident his side had put the heavy loss against New Zealand behind them and were up for the challenge of taking on the world champions in Avellaneda, where the game has been moved after the field at the original venue in Buenos Aires was declared unfit for the game.
“When we got back to work at the start of the week, everyone had a good attitude, very positive and have concentrated on the strategy for the game,” the coach said.
“It will be important to impose our way of playing. South Africa are a lot different to play against than Australia and New Zealand. It will be a different dynamic.”
Like all four teams in the southern hemisphere championship, Argentina won two and lost two of their first four games and are in the running for a first ever title.
“It is up to us to keep the Rugby Championship open and alive,” Cheika added.
Team: 15-Juan Cruz Mallia, 14-Emiliano Boffelli, 13-Jeronimo de la Fuente, 12-Matias Orlando, 11-Lucio Cinti, 10-Santiago Carreras, 9-Gonzalo Bertranou, 8-Pablo Matera, 7-Marcos Kremer, 6-Juan Martin Gonzalez, 5-Tomas Lavanini, 4-Matias Alemanno, 3-Eduardo Bello, 2-Julian Montoya (captain), 1-Nahuel Tetaz Chaparro
Replacements: 16-Agustin Creevy, 17-Thomas Gallo, 18-Joel Sclavi, 19-Guido Petti, 20-Rodrigo Bruni, 21-Tomas Cubelli, 22-Benjamin Urdapilleta, 23-Matias Moroni.
