New Delhi: That Australia's unbeaten run came to a halt in this World Cup is only evidence that the chinks in their once watertight armour are showing signs of falling apart and India will look for those openings to gun down the defending champions in the quarterfinal at Ahmedabad on Thursday.

There is no denying the fact that Australia have failed to recover from the succedent retirements in the last decade. The exodus of stalwarts like Glenn McGrath, Steve Waugh, Shane Warne and Adam Gilchrist has turned the invincibles into vulnerable.

Cut to 2011 and we find Australia getting seriously tested – with their 34-match, 12-year unbeaten streak in World Cups ended and wheels coming off whenever put under pressure.

There are quite a few weak links that render Australia defenceless in this World Cup, but the four that have set the alarm bells ringing in the Australian camp must be giving Ricky Ponting sleepless nights.

Innocuous spinners: With a World Cup in the subcontinent, where pitches have no grass for the fast bowlers to graze on, spinners rule the roost. But in the form of Jason Krejza and Steve Smith, Australia have arrived with possibly their weakest spin attack ever. Both have featured in all the six league encounters and while Krejza has a poor tally of five wickets, Smith has claimed just a solitary victim.

Ricky Ponting's poor run: The two-time World-Cup-winning skipper has looked a shade of his usual consistent self that earned him mentions in the same breath as Brian Lara and Sachin Tendulkar. He came into the mega event looking to shrug off his bad patch but with 102 runs in six matches at a trivial average of 20.40, he has failed to get the monkey off his back.

Inconsistent support for Brett Lee: Australia's fast-bowling machinery is relying more or less solely on the veteran Brett Lee's (12 wickets in six matches) firepower and the others – Shaun Tait, Mitchell Johnson and Shane Watson – have failed to support Lee when the chips have been down; for instance, in the game against Pakistan, where Lee bowled his heart out with a spell of 4/28 but had no support from the other end while defending a paltry 176. Further testimony to that could be found in the fact that minnows Kenya were able to play out their 50 overs against the defending champions.

Brittle middle order: Ricky Ponting's bad patch has uncovered a fragile middle order. Cameron White (58 runs from six matches), David Hussey (14 runs from three matches) and of late, Michael Hussey (66 runs in 3 matches) have failed to support the openers. And with Ponting too coming a cropper, the Aussie batting looks susceptible to better bowlers in the knockout phase.