After electing to field the previous 21 times he has won the toss, Marsh decided to bat in Australia's third and final ODI against South Africa in Mackay.
Australia only have pride to play for in the regional Queensland town after being thrashed in the opening two games.
Struggling allrounder Aaron Hardie has made way for his West Australian teammate Cooper Connolly, while star quick Josh Hazlewood has been rested ahead of a big summer.
Sean Abbott has been added to the XI as the replacement for Hazlewood.
Out-of-form No.3 Marnus Labuschagne has held on to his spot, despite scoring just two runs in the first two games.
South Africa captain Temba Bavuma returns to the line-up after missing Friday's 84-run win as the Proteas manage his workload following a hamstring injury suffered in June.
The Proteas have rested Matthew Breetzke, despite the middle-order batter top-scoring with 88 two days ago.
Star quick Lungi Ngidi will also sit out the match after claiming 5-42 for the second five-wicket haul of his ODI career.
AUSTRALIA: Â Mitchell Marsh (capt), Travis Head, Marnus Labuschagne, Cameron Green, Josh Inglis, Alex Carey, Cooper Connolly, Sean Abbott, Xavier Bartlett, Nathan Ellis, Adam Zampa
SOUTH AFRICA: Aiden Markram, Ryan Rickelton, Temba Bavuma, Tony De Zorzi, Tristan Stubbs, Dewald Brevis, Wiaan Mulder, Corbin Bosch, Keshav Maharaj, Senuran Muthusamy, Kwena Maphaka
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