Marsh backs "GOAT" Warner as Australia name final 15 for the ODI World Cup

In-form Australian all-rounder Mitchell Marsh has backed "GOAT" David Warner to continue opening the innings, conceding that he expects to bat in the middle order.

Marsh's impressive form across formats this year had led to talks that the all-rounder would compete with Warner and Travis Head for the opener's spot at the World Cup in India next month.

"I expect to bat middle order," Marsh told AAP (Australian Associated Press).

"Things may change, but Davey is literally one of the GOATs (greatest of all time) of one-day cricket and white-ball cricket in general.

"We have Travis Head and Australia's best-ever all-three-format player there, so I dare say I probably won't be opening the batting," added Marsh, who is leading the team in white-ball series against South Africa.

Warner, who has played most of his 142 ODIs batting at the top, returns to the squad for the five-match ODI series against South Africa, starting on Thursday in Bloemfontein.

Marsh, on the other hand, has been on a role this year. He had scores of 81,66 not out and 47 opening the batting in the ODIs against India earlier this year.

He then contributed during the Ashes before showcasing his batting prowess in the T20 against South Africa.

"My approach now from Test cricket to T20 cricket won't be too dissimilar, Marsh said.

"Often it's the situation of the game in Test cricket. There were times in Manchester where I couldn't go out there and try and hit blokes for six and put pressure back on them. I just had to soak up deliveries.

"That is the intricacies of Test cricket. But generally my approach won't change too much now," he added.