Cheika makes 7 changes to face world champion Boks
Reeling from a painful 53-3 thrashing by New Zealand in their last outing, Cheika decided to change both props, with Eduardo Bello introduced at loosehead and Nahuel Tetaz Chaparro at tighthead as Thomas Gallo and Joel Scalvi drop to the bench.
There are two more changes in the pack with Matias Alemanno recalled at lock and Juan Martin Gonzalez picked at blindside.
Gonzalo Bertranou gets the nod ahead of Tomas Cubelli at scrum-half, with Jeronimo De La Fuente returning from injury at outside centre and Lucio Cinti picked on the left wing.
Bertranou, Cinti, Gonzalez and Alemanno all started in the Pumas' historic first-ever win over the All Blacks in New Zealand three weeks ago, but were then dropped to the bench the following week when Argentina recorded their worst defeat to the three-time world champions since joining the Rugby Championship.
With two wins -- they also beat Australia 48-17 in San Juan last month -- and two defeats, Argentina remain in with a chance of winning the Rugby Championship for the first time.
They face an unchanged South Africa team from the starting XV that kept their championship hopes alive two weeks ago with a bonus-point 24-8 win in Australia.
The match will be played at the Libertadores de America stadium at 16:10 pm (1910 GMT) on Saturday after the original venue, the Jose Amalfitani stadium, failed a pitch inspection at the beginning of the week.
Team (15-1):
Juan Cruz Mallia; Emiliano Boffelli, Jeronimo De La Fuente, Matias Orlando, Lucio Cinti; Santiago Carreras, Gonzalo Bertranou; Pablo Matera, Marcos Kremer, Juan Martin Gonzalez; Tomas Lavanini, Matias Alemanno; Eduardo Bello, Julian Montoya (capt), Nahuel Tetaz Chaparro
Replacements: Agustin Creevy, Thomas Gallo, Joel Sclavi, Guido Petti, Rodrigo Bruni, Tomas Cubelli, Benjamin Urdapilleta, Matias Moroni