Furthermore, Willem Alberts has also been drafted back into the squad, pending a fitness test on Thursday when the squad gets together in Johannesburg.
Both Alberts and Matfield were part of the initial 30-man squad, but missed out on the victories over Argentina in Pretoria and Salta because of injury.
Van der Merwe will join the rest of the touring party in Johannesburg on Thursday. Malherbe will have to undergo surgery on his fractured ankle and is likely to miss the rest of the season because of this injury.
With Matfield and Alberts, if passed fit, returning for the two-week tour to Australia and New Zealand, Warren Whiteley and Juan Smith will drop out. Smith, however, will remain on standby if Alberts is deemed unable to tour.
“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,” said Springbok coach Heyneke Meyer.
“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.”
Meyer added that Whiteley had impressed him immensely during his week with the Springboks and that Smith had made a massive contribution during his time with the squad in the last fortnight.
“Warren and Juan know exactly where they stand and it was great to work with them, even if it was only for a limited period of time,” said Meyer.
The Springboks returned from Argentina on Monday and will enjoy a short break before reconvening in Johannesburg on Thursday. They are scheduled to depart for Perth on Saturday.
Springbok squad to travel to Australasia:
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.
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.