Indian captain Mahendra Singh Dhoni, who has just returned from South Africa after playing in the Champions League Twenty20, will also have to switch quickly from Twenty20 to Test mode for the series which coincides with the Commonwealth Games from October 3 to 14 in Delhi.

The same is the case for Dhoni's Chennai Super Kings team-mate Suresh Raina, who is set to play his third Test, though another CSK member Murali Vijay is expected to sit out.

But more than switching from shortest format to the longest, Dhoni's main worry would be the uncertainty over the fitness of off-spinner Harabhajan Singh who is suffering from an ankle sprain. With Mohali pitch predicted to be on the slower side with low bounce after heavy rains this monsoon season, slow bowlers, especially Harbhajan would be crucial to India's scheme of things.

In case of the feisty off-spinner's absence, who normally reserves his best against the Australians, Pragyan Ojha and Amit Mishra will have to take charge of the slow-bowling department.

"We will take a call on Bhajji tomorrow. The rest are all available for selection," Dhoni said at the pre-match media conference. While leg-spinner Amit Mishra has had a dream debut against the Australians in the 2008 series picking up five-for at this very ground, left-arm spinner Pragyan Ojha is a more disciplined bowler although a bit on the restrictive mould.

It has often been found out that Mishra has struggled on slow pitches as his leg breaks are rendered ineffective. Being too slow through the air has also been a problem.
Ojha, on the other hand, has the ability to keep the batsman quiet with tight line and length bowling. He gives an option to the bowler at the other end to have a go at the batsman.

The team-management will also have to take a call between pacers Ishant Sharma and S Sreesanth to share the new ball with experienced but injury-returned Zaheer Khan. It will be a tough call considering that both have not been in their best of shape and form at the international level. Ishant has been struggling in the past season and bowled well in patches during the Test series in Sri Lanka. Sreesanth couldn't make much of an impact during the three-day game against the Australians after recovering from a knee injury which led him to return home from Sri Lanka without playing a Test.

Ishant holds the edge if one goes by the record against Australians. He is one bowler who has earned the respect of the Australians after he made rival captain Ricky Ponting his bunny during his first tour of Australia in early 2008.

His ability to hit the deck hard and bring the ball back into the right handers makes him a better option against the Australians. Strike bowler Zaheer is also playing his first Test after seven months since India's second Test against South Africa in Kolkata in February.

The batting, however, looks formidable and settled with Gautam Gambhir coming into the mix after recovering from his injury while his opening partner Virender Sehwag was in terrific form in the Test series in Sri Lanka. Both came out unscathed of the injury scare just before the Test.

With their vast international experience, Rahul Dravid and Sachin Tendulkar should not have much of a problem in switching from Twenty20 cricket in the Champions League in South Africa to Test mode.

Dhoni and Raina are the other two players who have to switch off the Twenty20 mindset and change it to Test cricket while stylish VVS Laxman would be fresh after a break since the Sri Lanka tour.

The Australians, on the other hand, seemed to have acclimatise to the Indian conditions having been here for more than a week and done reasonably well in the three-day tour game though they also have to tackle with the Test match fitness of batsman Mike Hussey and pacer Dough Bollinger.

Hussey and Bollinger have just returned after winning the second edition of Champions League Twenty20 in South Africa for Dhoni-led Chennai Super Kings and the team-management had said they would not be automatic starters tomorrow. With the likes of captain Ricky Ponting, his deputy Michael Clarke, opener Simon Katich, all-rounder Shane Watson and Hussey, Australians have an experienced batting line-up.

Watson, Katich and Marcus North are in good knick with a century each against Board President's XI in the tour game. But their weak link would be the bowling department with left-arm pacer Mitchell Johnson leading the pace attack while 15-Test old right-arm off-spinner Nathan Hauritz would be the spin spearhead.

Ben Hilfenhaus, who has played 11 Tests, and uncapped Peter George could join Johnson if Bollinger is not fielded and Australia go with three-prong pace attack. Two-Test old Steven Smith is the other spin option if Australia decide to go with two spinners. For Ponting, it would be a chance to improve his record in India having had a moderate success here and with criticism from former Australian cricketers that he has crossed his prime with less than impressive performance off late.