Australia opening batsman David Warner has downplayed Sachin Tendulkar's poor recent form and says Test cricket's record run-scorer is simply a legend.

However, at 39 and without a century in the longest form of the game for two years, many observers are wondering if it's time for the little master from Mumbai to give a younger player an opportunity.

"A guy with over 25,000 first-class runs, you can't really say too much besides he's a legend," Warner told reporters in Chennai ahead of Friday's first Test.

"He's got the stats. He's got the experience.

"We're playing in his home territory.

"We know what we can expect from the great man. He can come out and score a hundred off a hundred balls."

Tendulkar averaged under 40 on the tour of Australia in 2011-12 but Warner says now's not the time to under-estimate the right-hander.

"The (Aussie) guys sort of worked him over," Warner said.

"But in these conditions (with less bounce) we've got to be more switched on and adapt straight away because otherwise he'll get on top of you.

"If we're just marginally off, then they're going to punish us."

Tendulkar scored an unbeaten century to guide India to a six-wicket victory in the most-recent Chennai Test in 2008 against England.

Warner says a player of Tendulkar's class will never lose his x-factor.

"He's just come out and scored a hundred in the Ranji Trophy. The mannerisms I saw from him when the last four wickets fell in that game, it still shows the passion he has for the game," Warner said.

"He was disappointed the way that the guys got out. You don't see a guy of his class shake his head too often and to see him shake his head shows he's got his heart on his sleeve.

"He's going to come out and try and show people what he's still made of.

"I think he wants to prove to himself that he's still got it."

Australia captain Michael Clarke also noted Tendulkar's recent first-class hundred.

"He's a huge player for India," Clarke said.