Justin Langer predicts Ashton Agar's shock axing for Australia's Twenty20 World Cup opener will be the first of several tough calls for him in the UAE.

Finger spinner Agar, the nation's top-ranked bowler in the format, was the unlucky omission for the win over South Africa as Australia went with three quicks.

The decision allowed selectors to unleash Josh Hazlewood, Mitchell Starc and Pat Cummins in the same T20 attack for the first time in the five-wicket win.

Agar has been a mainstay in Australia's T20 side in recent years, while Kane Richardson also missed out despite Langer labelling him the team's best death bowler.

Both Langer and captain Aaron Finch claimed Saturday's selection was largely about match-ups and starting strong in the powerplay, which proved crucial throughout the IPL on the same grounds.

But Sunday night's win potentially left Australia with even more questions for the rest of the tournament as they head to Dubai for Thursday night's clash with Sri Lanka.

Wickets are expected to get slower as the tournament goes on, potentially paving the way for a return to two spinners and only two frontline quicks if Australia opts for seven batsmen.

Hazlewood (1-19) and Cummins (2-17) have rarely been in Australia's T20 team in recent years, but were by far their best bowlers in Abu Dhabi.

Starc is Australia's best white-ball bowler and an x-factor with the ball, but was loose in the win over South Africa while finishing with figures of 2-32.

"They're all tough decisions. There's no doubt about that," Langer said.

"We've said from day one to the players and we did it in the last World Cup and to a degree in the last Ashes in England.

"We'll just look at the conditions, we'll look at the opposition, we'll look at the matchups, and we'll make the call that we think is right for the team.

"It doesn't always work out that way. But with all the information we've got we'll work through that."

Langer's comments come after Marcus Stoinis predicted that all 15 members of Australia's squad would play during the tournament.

Stoinis and Mitch Marsh were not required to bowl against South Africa as Glenn Maxwell got through four overs, but the trio's inclusion has allowed Australia to play seven batsmen.

Maxwell even took the new ball and removed Temba Bavuma in a two-over powerplay spell that went for just 11, with his bowling traditionally relied on more with Finch as his captain.

"I can't emphasize enough how tough it was on Ashton Agar, his numbers are literally outstanding," Langer said.

"And really tough on Kane Richardson.

"It's nice to have those selection headaches, but it worked okay yesterday."