KANPUR: The indifferent form of spin legend Muttiah Muralitharan is a cause of worry going into the series decider in Mumbai, Sri Lankan captain Kumar Sangakkara said here on Friday.

"It does bother us when our star bowler does not pick too many wickets when we know he can," Sangakkara said after Sri Lanka were thrashed by an innings and 144 runs in the second Test against India to go down 1-0 in the series.

"But he still is our best bowler and we've got to back him 100 percent because he will come good at some point, hopefully in the next game."

The 37-year-old off-spinner conceded a whopping 175 runs off his 37 overs while picking up two wickets as India galloped away to amass 642 runs in their first innings at the Green Park stadium.

Muralitharan, the world's top Test wicket-taker with 788 scalps, has been Sri Lanka's leading bowler for several years now, but there has been talk of his waning magic over the last three years.

He finished the drawn first Test in Ahmedabad with figures of 3 for 221 from 63.5 overs, of which only one victim was a top-order batsman.

The bowler also struggled on the last day, finishing wicketless for only the seventh time in the second innings, but the first time when he had bowled 20 overs or more.

Muralitharan is playing his last Test series overseas, after having announced in July his intention to quit the longest form of the game next year owing to a troublesome knee.

With a Test win on Indian soil still eluding the Sri Lankans, Sangakkara can only hope for Muralitharan to find form before the third and final Test begins in Mumbai on December 2.

"We still have got a lot to achieve in Mumbai," said Sangakkara.

"We can still draw the series 1-1. So there is great motivation for us. We are definitely disappointed but you have to take responsibility and move ahead."