Dinesh Chandimal has been ruled out of the World Cup due to the hamstring strain he suffered in Sunday's match against Australia. Kusal Perera, who has been training with the squad in Australia since last week, has been included into the squad, coach Marvan Atapattu confirmed.

Chandimal tweaked a hamstring in his right thigh when attempting a tight second run in the 41st over in Sydney. He immediately called for on-field treatment, but despite a rest and a rub-down, was significantly hampered by the injury.

He stayed at the crease to complete his fifty, but was forced to retire hurt in the 42nd over, when running between the wickets proved too difficult. His 52 not out off 24 balls - in his first World Cup innings - had done much to raise hopes of a successful Sri Lanka run chase. Their challenge petered out after his exit.

Kusal Perera has largely played as an opener over the past two years, but if he enters the XI, he is likely to resume batting in the middle order, where he had begun his career. He had been flown into Sydney as cover last week, when Dimuth Karunaratne suffered a blow on his hand that ruled him out of the tournament. Kusal arrives with a little form behind him. He hit a 68-ball 74 and a 69-ball 108 not out in a first-class encounter at home a few days before he set out for Australia.

Chandimal is the fifth Sri Lanka player to sustain an injury during Sri Lanka's campaign. Fast bowler Dhammika Prasad, slow-bowling allrounder Jeevan Mendis and batsman Karunaratne have already been ruled out of the tournament, and Rangana Herath is still recovering from a cut to his spinning finger. Herath is also unavailable for the match against Scotland.

Sri Lanka's chief selector Sanath Jayasuriya said that an injury like the one Chandimal suffered could happen during a long tour and stated it the timing was unfortunate as the batsman was in form.

"Chandimal's injury is a big blow because in Australia he has been performing really well. If you see his past record he has been really good," Jayasuriya said. "The way he batted against Australia was his natural game he should continue the way he is batting all the time.

"The team has been touring New Zealand and Australia since last December and obviously you'll tend to get some sort of injuries when you are on tour for such a long time, it's natural."

Jayasuriya also credited the work of psychologist Jeremy Snape and coach Marvan Atapattu for instilling confidence in Chandimal when the batsman was going through a lean patch. SLC had brought Snape on board for a stint during the World Cup.

"When you go through a bad patch and when you are not coming out of it you need to get your mind right - the way you play your cricket everything you tend to forget," Jayasuriya said. "It's altogether not about your batting skills, we practice virtually every day but at the end of the day it comes down to your mind. He has been preparing himself for this game and he batted really well.

"When you are not playing well as a human being, you go through a lot of things. Jeremy worked with him a lot on his mind, including Marvan (Atapattu) and the rest of the support staff. They did a lot of work with him and at the end of the day it's how you feel for yourself. Snape has been working with some of the players individually."

With inputs from Sa'adi Thawfeeq