Rohit Sharma begins training for Sydney Test as T. Natarajan is added to squad

Australia looking to field David Warner who might not be fully fit

Rohit Sharma is almost certain to play the Sydney Test. AFP

The Indian team welcomed star batsman Rohit Sharma back into their fold as he began training ahead of the third Test against Australia.

Sharma is fighting to be match ready for the match which begins in Sydney on January 7. He joined the team in Melbourne after spending two weeks in quarantine in Sydney after joining the tour late following a hamstring injury.

The limited overs opening batsman is almost guaranteed to start the Test, having been named the vice-captain of the team.

If Sharma is match-fit, he will most likely replace the out-of-form Mayank Agarwal. However, that would mean he would walk straight into opening the innings against the likes of Mitchell Starc, Pat Cummins and Josh Hazlewood having not played competitively for two months.

Also, left-arm seamer T. Natarajan was named as the replacement for injured paceman Umesh Yadav ahead of the last two Tests against Australia.

Yadav bowled only 3.3 overs in Australia's second innings in the second Test before limping off as India went on to level the series 1-1 with an eight-wicket victory in Melbourne.

The 33-year-old will miss the remaining matches in Sydney and Brisbane in the latest injury setback to the tourists, who are also without regular captain and batting mainstay Virat Kohli, who has returned to India for the birth of his child.

"The fast bowler will not recover completely ahead of the remaining two test matches and has been ruled out of the series," Jay Shah, the secretary of India's cricket board, said in a statement.

Veteran seamer Ishant Sharma missed the entire tour with a side strain while experienced paceman Mohammed Shami was ruled out after fracturing his forearm while batting in the opening match in Adelaide.

Natarajan, 29, was initially picked as a net bowler for India's tour Down Under after his strong showing in the Indian Premier League T20 tournament.

Shardul Thakur, who made his Test debut against the West Indies in 2018, replaced Shami in India's squad ahead of the Boxing Day Test and is likely to get the nod for the third Test. Thakur has the ability to swing the ball and is a more than capable batsman.

Meanwhile, Australia assistant coach Andrew McDonald said David Warner may play the third Test against India even if he is short of full fitness.

Warner was ruled out of the first two Tests in Adelaide and Melbourne after tearing an adductor muscle, but has been included in the 18-man squad for the match in Sydney.

With opener Joe Burns dropped after a woeful Melbourne Test, Australia will have a new opening partnership as they look to rebound from an eight-wicket defeat and take a 2-1 lead in the series.

McDonald said having Warner pad up if not completely fit would be a "clear option" and a matter for the player and head coach Justin Langer.

"He may not be 100 per cent. Who is coming off an injury? You never know until you get out there," McDonald said.

"Look, if he's 90-95 per cent fit and the conversation is that he's fit enough to be able to go out there and perform his duties for the team, then I'm sure that'll be a conversation the coach has with the player.

"Most times Justin is pretty open with the players in terms of giving them accountability around that."