Sydney- Australia are not sweating on Sunday's crunch Pool A match against Sri Lanka, even if defeat at the Sydney Cricket Ground would make their path to the final more difficult, opener Aaron Finch said today.

After losing to New Zealand and taking just a point from their washed out match against Bangladesh, Australia probably need to beat Sri Lanka to ensure they finish in the top two in the pool and avoid India or South Africa in the last eight.

"I don't think it matters who you play, to win the World Cup you have to beat the best teams in the world," Finch told reporters.

"This is a big game, it's important. You don't want to finish in the bottom two in your group, it does make it a little bit harder in your path to the final, if you go that far.

"But, in general, we've been playing some really good cricket lately so it's not something we're afraid of. We're not afraid of losing, we think that if we stick to the basics, we can get the job done."

Australia have such depth in their squad that they were able to drop stalwart all-rounder Shane Watson for their record 275-run victory over Afghanistan on Wednesday.

Although Finch scored a century against England in Australia's World Cup opener, he followed that with innings of 14 against New Zealand and four against the Afghans in Perth.

He admitted to being nervous before every match but was not at all concerned about his form.

"I think I'm playing well, I guess a poor decision in Auckland, a half-decent ball and a nothing kind of shot in Perth," he said.

"So there's a few things to work on, but I still think I'm hitting the ball well, I'm batting well in the nets, I'm training as well as I can.

"So I think it's only a matter of time before I get runs again, hopefully it's sooner rather than later."

The 28-year-old showed his value to the team as a fielder on Wednesday after replacing Watson at first slip and taking a stunning catch to dismiss Afghanistan's Nawroz Mangal off the bowling of Mitchell Johnson.

"I think I made it look better than it was," he laughed. "It was a nice height for a diving catch and a nice pace."