Australia all-rounder Mitchell Marsh says the defending champions were confident of bouncing back from their opening defeat at the T20 World Cup declaring: "Our best is the best in the world".
Australia are set to keep faith with the same team Tuesday and Marsh said he was confident they can turn their fortunes around.
"I think that we've got a lot of confidence in our group that once we get on a roll we're going to be very hard to stop," Marsh told reporters.
"Obviously we didn't start well the other night, but we've got great self-belief.
"We know our best is the best in the world. So hopefully, we can turn it around against Sri Lanka.
"[It's] the nature of the tournament. You lose one game, your back is up against the wall. Hopefully we play well, get past that. Then we move on to England."
New Zealand beat Australia
Perth-born Marsh knows The WACA all too well and believes conditions at his home ground will give Australia the edge over Sri Lanka, who are largely dependent on their spin attack.
"We know these conditions very well. And the stadium should suit us more than them," said Marsh.
Marsh backed the team's quick bowlers Josh Hazlewood, Mitchell Starc and Pat Cummins, who were expensive against New Zealand, to come good at Perth.
"We'll certainly have an aggressive approach. I think certainly after the other night we'll see a big response from them," Marsh predicted.
Sri Lanka crush Ireland
Sri Lankan spinners Maheesh Theekshana and Wanindu Hasaranga played a key part in the team's opening nine-wicket cruise past Ireland on Sunday.
The pair troubled the Australians when they toured Sri Lanka in June but conditions are likely to be different in Australia.
"Hopefully spin doesn't play a huge factor in Perth and we can look to really attack them," said Marsh.
"They're two key bowlers and if we can get on top of them then I think we'll be ahead of the game."
Theekshana said Sri Lanka are oozing confidence after their thumping win over Ireland but were wary of the wounded hosts.
"They lost to New Zealand and we won, so we have got the confidence more than the Australian team," Theekshana, who returned impressive figures of 2-19 on Sunday, told reporters.
"Always nice to win a game and our hope is always to go for the four teams, so we have to beat them.
"They have very good fast bowlers and spinners also. They are last year's champions, so they have to bounce back if they want to be in the tournament."