Anil Kumble is well aware of the threat posed by spinner Ajantha Mendis during the upcoming three Test series in Sri Lanka.

Mendis claimed career-best figures of six for 13 runs from eight overs to help Sri Lanka win the Asia Cup final against India in Pakistan.

The spinner, with a total haul of 17 wickets, was named Man of the Tournament and India's one-day skipper Mahendra Singh Dhoni conceded that the spinner was the difference in the final saying his batsmen failed to pick Mendis, a fact echoed by leg-spinner Kumble.

"It's obviously not easy to pick Mendis," Kumble wrote in the Hindustan Times. "When you are struggling to pick a bowler out of his hand, the usual thing is to play him off the wicket."

The 23-year-old Mendis bowls a variety of deliveries, usually a mixture of off-breaks, top spinners, flippers and googlies.

"The safest option, when you're not quite sure which way the ball will turn, is to play straight. Some of our batsmen made the mistake of playing across the line and paid the price," added Kumble.

"We need to watch Mendis. But Test cricket is a different ball game as batsmen have more time to assess a bowler and come up with a method to tackle him. In limited-overs cricket, you're always looking to score and this can induce the mistake.

"Mendis uses a grip that you see quite often in tennis ball cricket, but to master this with a cricket ball takes some doing and he's obviously managed that.

"He bowled wicket-to-wicket and employed subtle variations. It's not that he spun the ball a lot but he showed that when you are accurate, all it takes is small movement to beat the stroke."

The first Test starts in Colombo on July 23.