Australia allrounder Mitchell Marsh has 10 days to shake off a groin injury before the third Test starts in Cape Town next Thursday.
Marsh's captain Steve Smith revealed on Monday after going down in the second Test in Port Elizabeth that the West Australian under was carrying a groin strain that forced him into the slips at the start of South Africa's run chase.
Marsh put down Aiden Markram from Josh Hazlewood in the second over and was replaced by his brother Shaun in the slip cordon after lunch when Smith was told Marsh was OK to run around in the field.
There is no reserve allrounder in Australia's 15-man touring party, but Smith did not seem too concerned with the fitness of his No.6.
Marsh scored 96 in the first Test at Kingsmead and backed it up with 45 in the second innings at St George's Park, having also taken two key wickets on day two.
Smith said he was confident Australia's fast bowlers are fit and firing after two Tests, with the trio of Pat Cummins, Mitchell Starc and Josh Hazlewood well placed to take part in the crucial third Test at Newlands.
"He's got a bit of a groin strain so he was struggling to move a little bit," Smith said.
"I was told at the break that he can actually run, so unfortunately he could've been out on the field when he was in the slips, but still should've taken that catch.
"But everyone drops it every now and again, I've been pretty guilty myself in recent times.
"I think all the quicks are going really well. I haven't heard today, but before today they were all feeling fine, so hopefully with a good 10-day break they can freshen up a little bit.
"In regards to Mitch Marsh, it's a good break now between now and the next Test match and he's telling me he'll be fine but we'll wait and see how things go."
Qantas tour of South Africa
South Africa squad: Faf du Plessis (c), Hashim Amla, Temba Bavuma, Quinton de Kock, Theunis de Bruyn, AB de Villiers, Dean Elgar, Heinrich Klaasen, Keshav Maharaj, Aiden Markram, Morne Morkel, Wiaan Mulder, Lungi Ngidi, Vernon Philander, Kagiso Rabada.
Australia squad: Steve Smith (c), David Warner (vc), Cameron Bancroft, Pat Cummins, Peter Handscomb, Josh Hazlewood, Jon Holland, Usman Khawaja, Nathan Lyon, Mitchell Marsh, Shaun Marsh, Tim Paine, Jhye Richardson, Chadd Sayers, Mitchell Starc.
Warm-up match: Australia beat South Africa A by five wickets. Report, highlights
First Test Australia won by 118 runs. Scorecard
Second Test South Africa won by six wickets. Scorecard
Third Test Newlands, Cape Town, March 22-26. Live coverage
Fourth Test Wanderers, Johannesburg, March 30-April 3. Live coverage