South Africa added fullback Zane Kirchner and hooker Chiliboy Ralepelle to their squad on Wednesday for the Rugby Championship matches in Australia and New Zealand next month.
The 26-man travelling party that did duty in Argentina this past weekend has been retained, with the duo the only additions for a trip that could break new ground.
This will be two tough weeks on the road against two of the best sides in the world and as we saw last weekend against Argentina, we still have a lot of hard work to do
Ralepelle, the third hooker in the squad, missed the trip to South America because of a back injury and will have to pass a fitness test before he is cleared to travel to Australia, with medical staff to make a final decision by Friday.
The squad will travel on Saturday for their fixtures against Australia in Brisbane on September 7 and New Zealand in Auckland a week later.
The Springboks have never beaten Australia in the Queensland capital and their last victory at Auckland's Eden Park was in 1937.
"This will be two tough weeks on the road against two of the best sides in the world and as we saw last weekend against Argentina, we still have a lot of hard work to do," South Africa coach Heyneke Meyer said in a SARU press release.
South Africa narrowly escaped defeat in a 22-17 win in Mendoza last Saturday.
"Australia may have lost their first two matches of the Rugby Championship, but they showed a marked improvement last weekend in Wellington," said Meyer.
"We let ourselves down in certain areas of the game in Mendoza and will have to fix those if we are going to be competitive against Australia."
South Africa currently head the Rugby Championship log on points difference from New Zealand after home and away victories over Argentina in the opening two rounds of 2013 competition.
Forwards - Lourens Adriaanse, Willem Alberts, Marcell Coetzee, Bismarck du Plessis, Jannie du Plessis, Eben Etzebeth, Siya Kolisi, Juandre Kruger, Francois Louw, Tendai Mtawarira, Coenie Oosthuizen, Chiliboy Ralepelle, Gurthro Steenkamp, Adriaan Strauss, Flip van der Merwe, Duane Vermeulen.
Backs - Bjorn Basson, Jean de Villiers (captain), JJ Engelbrecht, Bryan Habana, Zane Kirchner, Patrick Lambie, Willie le Roux, Ruan Pienaar, Jan Serfontein, Morne Steyn, Piet van Zyl, Jano Vermaak.