The reshuffled front row are the only changes to the starting fifteen from the one that held holders New Zealand to a thrilling 16-16 draw in Wellington.
Duane Vermeulen will again lead the Springboks as captain for this decisive clash in the high altitude of Salta.
Mtawarira, the most experienced Springbok prop in history, and Nyakane replace Steven Kitshoff and Frans Malherbe, while Mbonambi takes over the hooker duties from Malcolm Marx.
All three front rankers who started the Test at the Westpac Stadium in the New Zealand capital are due to make an impact off the bench against the Pumas on Saturday.
The “Beast”, who is set to make his 110th appearance in the Green and Gold jersey, will join Rugby World Cup winner Bryan Habana on 53 appearances in the Rugby Championship to equal the Springbok record for number of caps in the southern hemisphere competition.
South Africa can clinch the Rugby Championship for the first time since 2009 if they can manage to beat the difficult Pumas with a bonus point.
The two teams are due to meet each other again next week again in Pretoria in what will be the Springboks’ final home Test before the announcement of the official Rugby World Cup squad on Monday, August 26.
South Africa and Argentina have played three times before in Salta.
The first Test, in 2014, was won 33-31 by the Springboks, while the Pumas won the second encounter at the Estadio Padre Ernesto Martearena in 2016, also by two points (26-24).
The last encounter between the two countries in Salta was in 2017, when Eben Etzebeth’s team, playing in a special edition red jersey, triumphed by a winning margin of 18 points (41-23), which was also the Boks’ biggest Rugby Championship victory in Argentina.
Overall, The Springboks have played 14 Test matches in Argentina against the Pumas, with 11 victories, two defeats and one draw, for a win percentage of 79%.
Teams
Argentina
15 Emiliano Boffelli; 14 Santiago Cordero, 13 Matias Moroni, 12 Jeronimo de la Fuente, 11 Ramiro Moyano; 10 Nicolas Sanchez, 9 Tomas Cubelli; 8 Facundo Isa, 7 Javier Ortega Desio, 6 Pablo Matera (captain); 5 Marcos Kremer, 4 Matias Alemanno; 3 Juan Figallo, 2 Agustin Creevy, 1 Nahuel Tetaz Chaparro
Substitutes: 16 Julian Montoya, 17 Mayco Vivas, 18 Santiago Medrano, 19 Guido Petti, 20 Tomas Lezana, 21 Gonzalo Bertanou, 22 Benjamin Urdapilleta, 23 Joaquin Tuculet
South Africa
15 Willie le Roux, 14 Cheslin Kolbe, 13 Lukhanyo Am, 12 Damian de Allende, 11 Makazole Mapimpi, 10 Handre Pollard, 9 Faf de Klerk, 8 Duane Vermeulen, 7 Pieter-Steph du Toit, 6 Kwagga Smith, 5 Franco Mostert, 4 Eben Etzebeth, 3 Trevor Nyakane, 2 Bongi Mbonambi, 1 Tendai Mtawarira
Substitutes: Malcolm Marx, Steven Kitshoff, Frans Malherbe, RG Snyman, Francois Louw, Herschel Jantjies, Frans Steyn, Jesse Kriel.
