'Ashwin's fitness to be evaluated over next 48 hours' – Shastri

Shastri added that the spinner's fitness will be assessed over the next couple of days. He also gave an update on Rohit Sharma and Hardik Pandya, who have both recovered from their injuries, but are yet to achieve full match fitness.

"As far as Ashwin is concerned, we are going to take a look and evaluate over the next 48 hours," Shastri told presspersons on Sunday, 23 December. "Rohit Sharma looks good, he has made very good improvement. But then again, we have to see how he pulls up tomorrow. He looks good as of today. Pandya is fit."

Pandya, who was ruled out of the first two games because of a back injury, has made a comeback into the squad for the third and fourth Tests. The all-rounder's availability will likely give India a significant boost in the bowling department, where the pacers have been shouldering heavy workload.

"It gives you that option," Shastri agreed. "He hasn't played much first-class cricket though, he has played just one game after the injury. We have to be careful before we actually decide on whether he plays or not."

A bulk of India's runs in the series has been scored by Virat Kohli, Cheteshwar Pujara and Ajinkya Rahane in the middle-order, while the opening batsmen have struggled. The duo of Murali Vijay and KL Rahul have not been in good form.

"It's a big concern," admitted Shastri. "That responsibility, that accountability has to be taken by the top order. They have got the experience, they have got the exposure over the last few years."

The visitors' decision of fielding an all-pace bowling line-up without a specialist spinner in the Perth Test was a bold call, but it did not quite pay the dividends.

When asked if, in hindsight, the team management should have picked Ravindra Jadeja for that game, Shastri said, "The problem with Jaddu was that he took an injection four days after coming here. He had a stiff shoulder.

"So when you look at Perth, he was around 70-80% fit and we didn't want to [take that] risk. The last thing we wanted was for someone to break down after five overs."

India won Test matches in South Africa and England this year, but failed to convert those singular victories into series triumphs overseas. The visitors will want to change that trend against Australia.

"Third time lucky," quipped Shastri. "It's not often will you find that a team is travelling overseas and it is 1-1 in the series with two Test matches to go. The boys know what they can do, what they're capable of and what potential lies again."