Slim as a girl, strong as a boy and all of 19 in 2007, Adam Gilchrist termed Ishant Sharma "lethal" after his spell in Perth, a venue the tall fast bowler could rightfully call his second home. Four years later, Ishant will have another chance to step onto the same soil - experienced, eager and hungry.

Since 2007-08 - a period in which only Zimbabwe and Bangladesh have lost more Tests than Australia - the Invincibles have turned vulnerable. In the same period, India enjoyed the view from top of the ICC Test rankings for more than a year before being replaced by England. And Ishant's 128 wickets in 41 Tests so far have played a major role in that climb.

The year 2011 has been a mixed bag for Ishant. If missing the World Cup at home was a big setback, the IPL brought him back into form and subsequently the Indian team for the tour of the West Indies. He did well in the Caribbean – finishing as Man of the Series in the three Tests - but then came the deplorable England tour, which ended for him with an injury. Ishant recuperated to return for the home Test series against West Indies, in which the spin of R Ashwin and Pragyan Ojha made all the news. Ishant, manfully but unspectacularly, plugged away for five wickets in three Tests.

All this while a troublesome ankle kept him in the news before Ishant himself cleared the air by saying that the injury didn't require surgery. But with Zaheer Khan still uncertain for the Boxing Day Test, the selectors chose to use Ishant with care, resting him for the ODI series against West Indies. Smartly, they also booked him an early flight to Australia to acclimatise before spearheading the Indian attack.

This could be a marquee series for Ishant, where his fitness, form, temperament and ability to lead a young pace battery will be under scrutiny. Indian bowlers learned the fitness lessons the hard way in England, which – like Australia – was also a four-Test tour and ended with a long injury list to go with the whitewash.

If Zaheer were to miss out on the Boxing Day Test, Ishant will be the only bowler in the XI with the experience of playing in Australia. In this context, his performance in Perth on the previous tour flashes to mind. Though he managed just six wickets in three Tests on the 2007-08 visit, Ishant's bowling at the WACA (2 for 34 in the first innings and 1 for 63 in the second) announced him on the world stage.

His murderous spell to Ricky Ponting on the fourth morning was the highlight of a fiercely competitive and acrimonious series, and played a big role in India winning a famous overseas Test. His relentlessness was eye-catching and the sheer ferocity of his focus on unsettling Ponting will not be easily forgotten. Ishant dismissed Ponting both times in Perth and troubled him all series, as well as giving Michael Clarke some testing moments, and this duel is set to resume this tour.

"How can I forget Perth? This city gave me my real identity after my performance there. [VVS] Laxman bhai always says that Kolkata is his first home and Sydney is second. I would say that Delhi is my first home and Perth is second," Ishant was quoted as saying before leaving for Australia.

That the Australians have tried to simulate Ishant's bowling style in practice shows how highly the speedster is rated by the opposition. "The thought is try to get into Melbourne a little bit earlier and do some work earlier, be that on the bowling machine. We can work on angles and heights that Ishant Sharma bowls and try and replicate how he bowls," Australia's new coach Mickey Arthur said.

Playing Australia in Australia is an intimidating proposition. While the atmosphere can bring your best to the fore, it can also turn you into a bundle of nerves, especially when the Australians pounce on their opposition like a pack of wolves. Here, Ishant has to be a bit careful and not get carried away, especially with his ankle that stands a risk of getting injured again. And MS Dhoni is shrewd enough to realise that.

Now, as leader of an attack comprising two rookie pace bowlers in Umesh Yadav and Abhimanyu Mithun (six Tests between them), a medium-pacer yet to debut in Vinay Kumar, a left-arm spinner in Pragyan Ojha yet to play in Australia, and an offspinner in R Ashwin only three Tests old, Ishant had the difficult yet potentially rewarding task of inspiring his team-mates. In Perth four years ago he did just that, casting a spell over Australia's captain and leaving him with no reply, but Ishant's biggest challenge lies ahead. India cannot afford to fold like they did in England - they have already lost two players since naming their Test squad - and a fit, fast and feisty Ishant is crucial to their success. This, without doubt, is his toughest task yet.