Marsh batted at first drop and passed 50 three times in Australia's 4-1 T20 series loss, before also featuring in the top order in the 2-1 ODI series win.

Smith is far from certain to play in the T20 tournament in Dubai and Oman in October and November, with this summer's Ashes his top priority as he recovers from an elbow issue.

Australia have five T20s to play in Bangladesh early in August before they pick their World Cup squad, with several questions still surrounding selections.

With several front-line stars who featured in the IPL not in the Caribbean, Australia's positives were scattered on wickets similar to the worn ones they will likely play on at the World Cup.

Langer took heart from how left-handed batters Alex Carey and Matt Wade's handled the spinners in the ODIs, but only the latter is likely to feature in the T20 World Cup side.

Wade, meanwhile, is expected to captain Australia in the Bangladesh games in place of the injured Aaron Finch, after Carey took the mantle in the West Indies ODIs.

Australia coach Langer also praised Ashton Agar's performances, with his spot in the T20 side as a second spinner almost certain.

But it was Marsh, who was out of Australia's T20 side at one point last year, that Langer identified as the big winner.

"Mitch Marsh has been a real find there at No.3," Langer said.

"Certainly (he) has put his hand up

"That No.3 position is really interesting, depending on how Steve Smith comes up with his elbow injury.

"That (Marsh) adds real depth to our to our play."

Josh Hazlewood is the other man likely to benefit most.

The seamer has not been a regular part of Australia's T20 side for the past five years, and missed the 2019 one-day World Cup despite being fit after a back injury.

But he finished this month's West Indies white-ball tour with nine wickets at 16.11, and can further press his claims in Bangladesh.

"He was brilliant. He Is Mr reliable isn't he?" Langer said.

"And we were talking about last night with Starcy, Mitchell Starc and Josh Hazlewood, they just worked so well together.

"They're both relentless, and they just give the opposition nothing and particularly on wickets where there's a little bit there.

"To have someone like him to be able to play with the white ball, not just the red ball, that's a huge bonus for us he was brilliant.

"He did everything he possibly could to help us in the series and to for his prospects moving forward."

Australian Associated Press