Australia won the toss and decided to bowl in the third one-day international with South Africa in Potchefstroom on Tuesday.
With Australia holding a 2-0 lead in the five-match series, captain Mitchell Marsh announced three changes, including an ODI debut for leg-spinner Tanveer Sangha.
"Leading up to the World Cup we have a full squad and we want to give opportunities to all the players," said Marsh.
South African fast bowler Anrich Nortje was not considered for selection after suffering back spasms during the second match in Bloemfontein on Saturday.
South Africa made four changes, with captain Temba Bavuma saying, "it’s about pulling everything together."
"The batting has been good in parts but we want players to go on to big scores. Our death bowling was better (on Saturday) but we need to stop giving away soft boundaries."
Teams:
South Africa: Temba Bavuma (captain), Quinton de Kock (wkt), Reeza Hendricks, Aiden Markram, Heinrich Klaasen, David Miller, Marco Jansen, Sisanda Magala, Gerald Coetzee, Keshav Maharaj, Tabraiz Shamsi
Australia: Mitchell Marsh (captain), David Warner, Travis Head, Marnus Labuschagne, Alex Carey (wkt), Marcus Stoinis, Tim David, Sean Abbott, Nathan Ellis, Tanveer Sangha, Josh Hazlewood
Umpires: Bongani Jele (RSA), Richard Kettleborough (ENG)
TV umpire: Nitin Menon (IND)
Match referee: Richie Richardson (WIS)
str/dmc/bsp