Stand-in skipper George Bailey has called on Australia to pull together in the absence of regular captain Michael Clarke.
Clarke is still in London receiving intensive treatment on his back injury, meaning Bailey will again lead the side in Wednesday's must-win Champions Trophy clash against New Zealand at Edgbaston.
Victory would put the the reigning champions - who lost their tournament opener against England - in with a chance of progressing to the semi-finals, while defeat would almost certainly mean an early exit from Group A.
"It's something we've been preparing for," Bailey said after Clarke was formally ruled out.
"I don't think 'Pup' (Clarke) was ever going to come in and play a game without having trained so I think everyone assumed what was going on.
"He's our captain and our best batsman. We miss him every time he's not with us. But as any team does when your best players are out, the challenge is for someone to step up and fill the hole, or numerous people to fill the hole."
Australia's main problem appears to be a misfiring top order. They were rolled for 65 all out by India in a pre-tournament warm-up and fell well short of chasing a target of 270 against England.
"The batting has probably let us down and the challenge when you've had a couple of poor batting performances is that people start to doubt their place in the team or their role in the team," added Bailey.
"What we want is for our guys to have absolute clarity and bat the way we know they can bat."
New Zealand are without Grant Elliott (calf) and former captain Daniel Vettori will be face a fitness test on his Achilles in the morning after making his comeback from a long lay-off in the one-wicket win over Sri Lanka.
"Australia are a good side and they'll be disappointed in their performances over here so far," said New Zealand seamer Tim Southee.
"They're coming off a loss so they'll come out hard and have a point to prove with a long (Ashes) summer in front of them.
"They'll want to turn things around as quickly as they can and there's a whole rivalry between New Zealand and Australia where both sides tend to lift a little against each other."