The honour of captaining Australia sits lightly on Mitchell Marsh's shoulders as he prepares to lead the team in search of an unprecedented treble of major global titles at the T20 World Cup in June.

Marsh was confirmed as captain with the squad's naming on Wednesday, continuing a remarkable comeback for the laconic all-rounder since his recall during last year's Ashes.

The 32-year-old has already proved a popular and successful skipper, leading the team to series wins over New Zealand and T20 World Cup co-hosts West Indies.

His laid-back demeanour sits well with an Australian side who have reached great heights since parting ways with firebrand head coach Justin Langer.

Marsh said being selectors' faith in his leadership would do little to change him.

"One of the biggest things I've learnt is to not change too much," he told reporters on Wednesday.

"Obviously, there's a lot of preparation and planning that goes into a World Cup and that'll happen over the next month.

"But once we get there it's (about) keeping everything nice and relaxed, keeping the environment good."

Marsh took Australia's top cricketing honour when he won the Allan Border medal in January, recognition for his starring roles in the Ashes and Australia's sixth one-day World Cup title last year in India.

History beckons again, as Australia look to become the first nation to hold the global T20, one-day and Test championships at the same time with another triumph in the United States and Caribbean.

Though joking his way through Wednesday's press conference, Marsh put on his serious captain's hat when asked about the treble bid.

"It's not something we necessarily focus on as a group," he said.

"It would never have been done before so that will be special but there's so many things you've got to get through at a World Cup before you can even get a crack at that.

"That's probably for the external noise ... but I guess the carrot's there."