Lasith Malinga © Getty Images

Sri Lanka must decide whether to risk Lasith Malinga in their Super Eight match against New Zealand after it emerged the strike bowler has an ankle injury.

Malinga's unavailability would be a significant setback to Sri Lanka in Grenada on Thursday, but captain Mahela Jayawardene insists no unnecessary gambles will be taken.

“Lasith has an ankle problem, and we'll assess it over the next couple of days. We're not sure he's 100 per cent,” said Jayawardene.

Malinga did not take part in team practice on Tuesday, but the captain is not about to panic.

“We don't want to take unnecessary risks at this stage,” he said. “We've got experienced players who can come in - and we are confident they can do a job for us.”

While Malinga rests his left ankle, his most likely replacement is Farveez Maharoof or Nuwan Kulasekara.

“It depends on how much of a gamble we want to take at this stage,” Jayawardene added.

“He's had a scan, which has shown some minor ligament damage. But it's nothing serious.”

Malinga became the first bowler to take four wickets in four balls in international cricket in Sri Lanka's narrow Super Eight defeat against South Africa in Guyana.

The 23-year-old has taken 15 wickets in the tournament.