Sydney: Mitchell Marsh will take over Australia's captaincy for the white-ball tour of South Africa after Steve Smith and Mitchell Starc were ruled out with injuries.

Australia is also without the services of Pat Cummins, who is recovering from a fractured wrist that he sustained during the Ashes.

Smith is nursing a tendon injury to his left wrist that will take about four weeks to heal, while Starc has been experiencing groin soreness since his return from the UK, an ICC report on Friday said.

Both Smith and Starc are expected to be fit in time for Australia's ODI series against India and the ICC Men's Cricket World Cup. And have been given enough time to rest and recover before the coveted tournament begins.

"The compacted Ashes series and the World Test Championship was a heavy load for the group, and we are taking a conservative approach to the build-up to the World Cup," national selection panel chair George Bailey said.

"With the World Cup the priority of the squad, it was determined on advice that it was best for Steve Smith and Mitchell Starc to join the group in India by which time we expect them to be fully fit and available for the Indian ODI series, plus the World Cup warm-up fixture," Bailey said.

Meanwhile, Cummins is expected to join the team in the later stages of the South Africa tour.

Ashton Turner has replaced Smith in the T20I squad for South Africa, while Marnus Labuschagne and Spencer Johnson have replaced both Smith and Starc in the ODI squad.

The white-ball series comprises three T20Is, followed by five ODIs, and the tour begins on August 30 in Durban and concludes on September 17 in Johannesburg.

Australia T20 squad: Mitchell Marsh (c), Sean Abbott, Jason Behrendorff, Tim David, Nathan Ellis, Aaron Hardie, Travis Head, Josh Inglis, Spencer Johnson, Glenn Maxwell, Matt Short, Marcus Stoinis, Ashton Turner, Adam Zampa

Australia ODI squad: Mitchell Marsh (c), Sean Abbott, Ashton Agar, Alex Carey, Pat Cummins, Nathan Ellis, Cameron Green, Aaron Hardie, Josh Hazlewood, Travis Head, Josh Inglis, Spencer Johnson, Marnus Labuschagne, Glenn Maxwell, Tanveer Sangha, Marcus Stoinis, David Warner, Adam Zampa.

(With UNI inputs)