Marsh was recently named vice-captain of the Test side but didn’t fare well in the Test series against Pakistan, finishing with just 30 runs and two wickets in four innings. He didn’t have great success in the T20Is that followed either, managing just two wickets and 42 runs in the three games.
Australia's chairman of selectors Trevor Hohns, however, suggested Marsh and Nathan Lyon omission was “to ensure they are in the best condition possible to put their hand up for selection either later in the summer or for the World Cup next year."
However, Marsh was disappointed with his output. "Over the last three or four years, (50-over cricket has) been my best format,” Marsh told AAP. “But right now I'm not in our best XI. There's no doubt I want to be in that World Cup team. I want to be a leader in the one-day team as well.
"Right now I've got to get myself as fit as I can so I can play all three formats and be performing in all three formats for Australia.
"This is a minor setback but I still think that I can be in our best side throughout this summer."
The decision to drop him from the one-day side came on the back of Marsh being named as one of the two vice-captains of the Test side, having been made captain of the Australia A side that toured India for two four-day matches in August.
“You work so hard throughout the winter and to try and become better in these conditions. And it didn't come off this series.”
"It was shattering," Marsh said. "You work so hard throughout the winter and you work on so many things to try and be a better cricketer and become better in these conditions. And it didn't come off for me this series.
"I learnt a lot again. For me it's just about taking the opportunity. I know exactly what I have to do to play in the Test team and that's dominate Shield cricket and make sure they can't not pick me."
The first ODI against South Africa will be played in Perth on Sunday (November 4).
First Published: October 29, 2018, 4:52 PM IST