Cricket icon Sachin Tendulkar has issued a warning to triumphant India about their upcoming World Cup match against South Africa, saying the Proteas were "far, far superior" to arch-rivals Pakistan.

Batting superstar Tendulkar helped India win the World Cup four years ago with victory over Sri Lanka at his Wankhede Stadium home ground in Mumbai and also played in six World Cups before retiring from international cricket in 2013.

India started the defence of their title with a convincing 76-run win over Pakistan in Adelaide last Sunday, with Virat Kohli -- the new idol of his country's adoring fans in Tendulkar's absence -- making a brilliant 107.

However, Tendulkar said India would need a strong opening partnership and careful running between the wickets to beat South Africa, one of the pre-tournament favourites, in this coming Sunday's clash at the Melbourne Cricket Ground.

"It won't be so easy to pick singles," Tendulkar told Headlines Today TV on Monday.

"They (South Africa) are much faster, their throwing arm is more powerful and their outfielding ... they cover the area much better than Pakistan."

Tendulkar singled out South Africa's spearhead Dale Steyn as the man India's batsmen needed to fear.

"Without any doubt he's their strike bowler. He's bowled unbelievably well," he said.

"You can't pre-decide how to play Steyn, he could also have a bad day, you have to decide in the moment but you have to respect Dale Steyn, you need to be watchful upfront but take your opportunities."

Tendulkar also backed India opener Rohit Sharma to come good at the World Cup, despite managing just 15 runs against Pakistan, along with captain Mahendra Singh Dhoni who recently led the side on a miserable three-month tour of Australia.

"I wouldn't put any pressure on Rohit. Next time you'll get it right," said Tendulkar.

'The Little Master' also insisted India could retain the World Cup trophy, saying "definitely we can match up" to the standards of co-hosts Australia and South Africa.

"(But) To win the World Cup the whole team will have to play consistently play well... It's not just about a couple of individuals."