Michael Clarke insists he is “fitter and healthier” than he has been for a long time ahead of their Pool A match against 1996 champions Sri Lanka.
The Australian captain Clarke had been battling to be fit for the ICC Cricket World Cup 2015 after suffering recurring hamstring injuries in the build-up to the tournament.
A washout against Bangladesh and the emphatic 275-run victory over Afghanistan has restricted Clarke to facing just 18 balls in his injury-delayed start to the tournament.
"I feel, touch wood, that I'm fitter and healthier than I've been for a long time," Clarke told reporters ahead of the match with Sri Lanka at the Sydney Cricket Ground.
"I have that hunger inside me to be successful and help Australia to get as far as we possibly can in this World Cup.
"I've copped a fair bit of criticism over the last few months so I'm excited about what lies ahead. I'm at my best, I'm ready to help this team have success."
The 33-year-old, who will be playing at his home ground in Sydney, believes winning the toss could be a crucial factor in deciding the outcome of the game.
"Looking at the wicket today, if we were to play today, the toss would be crucial," he said. "If it's still a little bit tacky like it is today, then I'd really want to bat first."
Australian fast bowler Pat Cummins misses the game with a side strain while Sri Lanka batsman Dimth Karunaratne is out for the rest of the tournament with a broken finger.
Rangana Herath also misses the clash with Australia but leg-spinner Seekkuge Prasanna looks set for a start for Sri Lanka.
"They've got about seven right-handers, so he comes into play," Sri Lanka captain Angelo Mathews said.
New Zealand will be heavy favourites when play Afghanistan in the earlier game in Napier but Kiwi captain Brendan McCullum insists his side will not be underestimating their opponents.
"Their bowling looks quite strong, I think it's fair to say it's probably their strongest suit,” he said. “They've got three guys who bowl in excess of 140 (kmh/87mph) and have asked some questions of some very good teams.
"We think they certainly pose some dangers to us and we're going to make sure we're as up for this game as we have been for previous ones."
Coverage of New Zealand v Afghanistan followed by Australia v Sri Lanka begins on Sky Wolrd Cup HD at 9pm on Saturday night