Springbok coach Jacques Nienaber made 10 changes for the team’s second match of the season in New Zealand and then nine for the narrow 22-21 Rugby Championship victory against Argentina in Johannesburg last weekend.
He has continued to cast his net wide and manage the minutes of the players with a further 14 changes for Saturday’s test.
The only one to retain their place is flyhalf Manie Libbok, with regular starter Handre Pollard still working his way back from injury.
Fullback Damian Willemse and wings Canan Moodie and Makazole Mapimpi make up the back three, while Lukhanyo Am and Andre Esterhuizen are the centre-pairing. Cobus Reinach is back into the side at scrumhalf.
Props Thomas du Toit and Trevor Nyakane are either side of Mbonambi in a new-look front row, as Marvin Orie and former Ireland international Jean Kleyn, winning his second cap for the Boks, are at lock.
Jasper Wiese is in at number eight, with versatile loose-forwards Franco Mostert and Deon Fourie on the side of the scrum.
Steenekamp, in the squad as cover for the injured Ox Nche, will likely earn his first cap off the bench in the final game before Nienaber names his squad for their World Cup title defence in France next Tuesday.
"We’ve been emphasising the importance of giving as many players as possible a fair chance to show what they can do with an eye on finalising our Rugby World Cup squad," Nienaber said in a media release from South African Rugby.
"This is going to be a massive physical battle and there will be a lot of pressure on the players mentally and physically, which is exactly the type of situation we would like to see them in as we enter our World Cup warm-up games.
"There is not a player in our enlarged squad who is fully confident that he will be in the World Cup squad, so the competition for places is intense."
The Boks scraped a barely deserved win at Ellis Park on Saturday as they withstood intense pressure from Argentina, and will expect a backlash from the home side.
Springbok team: 15 – Damian Willemse, 14 – Canan Moodie, 13 – Lukhanyo Am, 12 – Andre Esterhuizen, 11 – Makazole Mapimpi, 10 – Manie Libbok, 9 – Cobus Reinach, 8 – Jasper Wiese, 7 – Franco Mostert, 6 – Deon Fourie, 5 – Marvin Orie, 4 – Jean Kleyn, 3 – Thomas du Toit, 2 – Bongi Mbonambi (captain), 1 – Trevor Nyakane
Replacements: 16 – Joseph Dweba, 17 – Gerhard Steenekamp, 18 – Vincent Koch, 19 – Jean-Luc du Preez, 20 – Evan Roos, 21 – Herschel Jantjies, 22 – Jesse Kriel, 23 – Kurt-Lee Arendse
