Shane Watson advises Australia on facing Ravindra Jadeja and Ravichandran Aswhin

Ashwin and Jadeja have been included in the hosts' squad for this month's Tests against Australia - and will likely feature in the same XI for the series opener in Nagpur.

"Facing Jadeja when the ball is turning compared to when the ball is not turning is just chalk and cheese," Watson told ESPNcricinfo. 

"It's like you're facing a different bowler when the ball is turning because he's flatter, he's faster, he's accurate all the time. He's always at the stumps.

"One will turn or one will skid through. He's very hard to be able to work through as a right-hander, to find a method that's going to not just survive but also score runs."

Watson played 59 Tets between 2005 and 2015. Nine were played in India. He also had several stints in the Indian Premier League with the Chennai Super Kings and other franchises.

"It's a bit easier as a right-hander but when the ball is turning and sort of jumping out of either the rough or the fresh part of the wicket, Ashwin is relentless," he added. 

"He hardly gives you a free ball to be able to score off. He's incredibly skilled. It's not just getting the ball spinning with the occasional one that's not going to turn. He's got a lot of variations through his flight and pace that he still can land exactly where he wants. 

"So even as a right-hander, when the ball's not turning that much it's a much easier challenge. I just batted on off stump and hit straight to the leg side knowing that unless one really explodes and I get caught at bat-pad, I'm not really exposed to that.

"Whereas when the ball is turning, coming back into my stumps, it's much more challenging to be able to try and cover that ball coming in when there's plenty of guys around the bat."

Delhi, Dharamsala and Ahmedabad will host Tests two, three and four, respectively.