Last week, the Springboks boss stated the team for the second Test against the Wallabies had already been announced internally, but due to performance in the 38-22 defeat, the coaching staff have tweaked the matchday 23.
Injuries have also forced the coach's hand with Siya Kolisi, Kurt-Lee Arendse, Pieter-Steph du Toit, and Edwill van der Merwe ruled out of the round two fixture in the Rugby Championship.
Erasmus has made ten changes to his starting XV in total, with Willie le Roux, Canan Moodie, Damian de Allende, Cheslin Kolbe and Handre Pollard named in the backline, while Jean-Luc du Preez, RG Snyman, Franco Mostert, Ruan Nortje and Thomas du Toit start in the pack.
While wholesale changes were expected, the Bok boss confirmed there were players who were in line to make an appearance in Cape Town, but ultimately missed out due to the performance in Johannesburg.
"With the result of us losing momentum, four guys miss out, Krappies [Morne van den Berg], Ethan [Hooker], and Vincent [Koch]," Erasmus explained, with the fourth player likely being Cobus Wiese, whose name escaped the head coach.
"There are four guys who would have played this weekend. Hopefully, we can get back on the horse and win again.
"Then obviously a guy like Kurt-Lee [Arendse] might have backed up, and Canan [Moodie] might have played at centre if we had won - those guys missed out there, and there are also injuries in other positions."
On Monday, it was announced that Kolisi and Arendse had been released from the squad, with Makazole Mapimpi called in as cover for the latter.
Erasmus stated that no additional cover would be called in for Kolisi just yet and explained his loose forward selections for this week, with Franco Mostert featuring at blindside flanker after Pieter-Steph du Toit ruled out due to a concussion, and he joins Marco van Staden and Jean-Luc du Preez in the back row.
"I don't think there is an eighthman crisis. Jasper Wiese is currently banned, so he'll be back soon," he said.
"I thought Siya was actually excellent last week, he scored a try, he helped a lot at the breakdown, but unfortunately, he was on the wrong end of an incident.
"Kwagga when he came on, one or two balls that he stole, were unfortunately deemed to be off his feet, or that the ball wasn't out. Still, he made a real impact.
"So I don't think the eighth man position lost us the game. We're not going to bring in somebody new â- we believe the guys we have here are doing the job. It's difficult to keep such a big squad happy and give everyone game time.
"Everyone has asked many times, when is Jean-Luc going to get a proper chance? So now it's his chance, and hopefully it goes well.
"Unfortunately, Pieter-Steph has a concussion. We've got a couple of options at 7, but Mostert has done it many times for us.
"He's close to what Pieter-Steph gives us, he is probably the fittest in the team, he knows the system, and he knows what we want. We all know what we did wrong last weekend.
"Knowing what you did wrong is easy - fixing it is not always that easy. But we feel a guy like him will help us in the lineout, and in general and when the game gets loose, he can tidy it up."