Cheika has made two selection changes, bringing in wing Juan Imhoff and centre Matias Moroni for Lucio Cinti and Matias Orlando. That follows South Africa also making two changes when naming their line-up on Tuesday, with Frans Steyn coming in at fly-half for the injured Damian Willemse, and flanker Pieter Steph du Toit stepping in for Franco Mostert.
Argentina team: Juan Cruz Mallia, Emiliano Boffelli, Matias Moroni, Jeronimo de la Fuente, Juan Imhoff, Santiago Carreras, Gonzalo Bertranou; Nahuel Tetaz Chaparro, Julian Montoya (captain), Eduardo Bello, Matias Alemanno, Tomas Lavanini, Juan Martin Gonzalez, Marcos Kremer, Pablo Matera.
Replacements: Augustin Creevy, Mayco Vivas, Joel Sclavi, Guido Petti, Pedro Rubiolo, Tomas Cubelli, Benjamin Urdapilleta, Bautista Delguy.
South Africa team: Willie le Roux, Canan Moodie, Jesse Kriel, Damian de Allende, Makazole Mapimpi, Frans Steyn, Jaden Hendrikse; Steven Kitshoff, Malcolm Marx, Frans Malherbe, Eben Etzebeth, Lood de Jager, Siya Kolisi (captain), Pieter-Steph du Toit, Jasper Wiese.
Replacements: Bongi Mbonambi, Ox Nche, Vincent Koch, Franco Mostert, Duane Vermeulen, Kwagga Smith, Faf de Klerk, Kurt-Lee Arendse.