Veteran lock Victor Matfield will join the Springboks for their trip to Australia and New Zealand.
Matfield, 37, has been passed fit to tour with the Boks now just waiting for final confirmation on big loose forward Willem Alberts who has also been struggling with injury.
Both Alberts and Matfield were part of the initial 30-man squad, but missed out on the squeaky victories over Argentina in Pretoria and Salta because of injury.
Alberts would need to pass a fitness test in Johannesburg on Friday before the team heads to Perth to prepare for their next assignment in the Rugby Championship, playing the Wallabies on September 6.
They play the All Blacks in Wellington the following weekend.
The Boks have two wins to top the table, but have been far from convincing as they prepare for a tough road trip.
The Boks have also called up Marcel van der Merwe for the injured prop Frans Malherbe.
Loose forwards Warren Whiteley and Juan Smith drop out of the squad.
Having Matfield, the talisman of their pack with 113 tests to his name, return would be a boost for the Boks whose scrum was very shoddy against the big Pumas pack.
With an unsettled set-piece, the Boks struggled for any fluency.
"Victor is over his injury and has been declared fit to travel with us for the next two tests, while we're awaiting a final verdict on Willem," Springbok coach Heyneke Meyer confirmed.
"It will be good to have them back. Willem has been part of the squad for the last number of seasons and Victor showed he can still add a lot of value when he returned to the Bok fold earlier this year.
"Losing Frans is a huge setback and my heart bleeds for him, because he's done well since returning from a long injury lay-off recently which saw him miss the June tests.
"It's also a big disappointment for Frans, whose involvement with the squad was cut short because of injury last November as well, but Marcel has been with us before and will slot in seamlessly. He provides specialist tighthead cover as Tendai Mtawarira, Gurthrö Steenkamp and Trevor Nyakane are specialist looseheads."
Springboks squad to tour Australia and New Zealand
Forwards: Willem Alberts, Bakkies Botha, Schalk Brits, Marcell Coetzee, Lodewyk de Jager, Bismarck du Plessis, Jannie du Plessis, Eben Etzebeth, Francois Louw, Victor Matfield, Teboho Mohoje, Tendai Mtawarira, Trevor Nyakane, Gurthrö Steenkamp, Adriaan Strauss, Marcel van der Merwe, Duane Vermeulen.
Backs: Damian de Allende, Jean de Villiers (captain), Bryan Habana, Cornal Hendricks, Francois Hougaard, Patrick Lambie, Willie le Roux, Lwazi Mvovo, Ruan Pienaar, Handré Pollard, Cobus Reinach, Jan Serfontein, Morné Steyn.
Who was the better Springboks lock?