World Cup winger JP Pietersen and uncapped hooker Schalk Brits have been added to the Springbok squad for the second Test against Wales in Johannesburg on Saturday, a team spokesperson said.
Pietersen and Brits have been invited to join the squad for training, despite not being in coach Peter de Villiers's 30-man squad announced last month.
"JP and Schalk are both in contention for selection," Springbok communications manager Chris Hewitt told reporters on Tuesday.
"We're going to lose John Smit shortly for his French commitments and it makes sense for Brits to get familiar with the lineout calls," Hewitt said.
Hooker Smit will miss the Test against Italy in Cape Town on June 21 as he has been released to his French club Clermont to play in the Top 14 semi-finals.
"JP was a vital part of our World Cup win and it would be absurd to just abandon him. He knows he is part of our plans, but by his own acknowledgement he was not in the best conditioning in the pre-season," Hewitt added.
"The decision to keep him with the squad is more to monitor him, to make sure he is keeping to the conditioning programs he has been given and to keep him in the right mindset."
The Springboks will work on their scrummage on Tuesday afternoon, the one area where Wales dominated during South Africa's 43-17 victory in Bloemfontein last weekend.
Wales have delayed naming their team until Thursday.