Veteran India spinner Ravichandran Ashwin has been ruled out of the fourth Domain Test in Sydney.

Ashwin is not 100 per cent fit and has not been considered for selection, India captain Virat Kohli confirmed on the eve of the SCG showdown.

UPDATE: Ashwin a last-minute addition to India's Test squad. More here

The off-spinner sustained a side strain in the first Test in Adelaide and has missed the past two Tests.

He had earlier trained with the Indian side at the SCG as the fine-tuned for the Test where they will bid to become the first side form India to ever win a series on Australian soil.

Left-arm orthodox spinner Ravindra Jadeja played in Melbourne and claimed five wickets and looks set to retain his place on an SCG pitch that is expected to take turn.

It's now the second Test series Ashwin hasn't finished due to injury following the five-match tour of England last winter.

Captain Virat Kohli said Ashwin's unavailability was a big blow to his side.

"It's unfortunate that he's had two niggles that are quite similar in the last couple of away tours," Kohli said."It's something he will focus on to correct.

"The physio and trainer have spoken to him about what he has to do.

"He's very important for sure. In Test cricket he's a vital part of this team and we wanted him to be 100 percent fit for a longer period to that he can come back to us in the Test format. He is very disappointed that he's not able to recover in time."

Kohli added that the part-time spin of Hanuma Vihari was a wicket-taking option for his side in Sydney.

"The Ashwin factor, it does make you alter your plans a little bit. But Vihari was bowling beautiful whenever he got the ball," Kohli said.

"Vihari has looked like picking up a wicket every time he comes on to bowl. We are looking at him as a solid bowling option now, especially in this Test match."

India will need to make at least one change to the team that won in Melbourne with middle-order batsman Rohit Sharma, who hit a gritty 63 in the first innings, jetting back to Mumbai after his wife gave birth to a daughter.

Domain Test Series v India

Dec 6-10: India won by 31 runs

Dec 14-18: Australia won by 146 runs

Dec 26-30: India won by 137 runs

Jan 3-7: Fourth Test, SCG

Australia squad: Tim Paine (c, wk), Josh Hazlewood (vc), Mitch Marsh (vc), Pat Cummins, Aaron Finch, Peter Handscomb, Marcus Harris, Travis Head, Usman Khawaja, Marnus Labuschagne, Nathan Lyon, Shaun Marsh, Peter Siddle, Mitchell Starc

India squad: Virat Kohli (c), Murali Vijay, KL Rahul, Mayank Agarwal, Cheteshwar Pujara, Ajinkya Rahane, Hardik Pandya, Hanuma Vihari, Rohit Sharma, Rishabh Pant (wk), Parthiv Patel (wk), Ravi Ashwin, Ravi Jadeja, Kuldeep Yadav, Mohammed Shami, Ishant Sharma, Umesh Yadav, Jasprit Bumrah, Bhuvneshwar Kumar