Mumbai Indians head coach Ricky Ponting expects Lasith Malinga to miss at least half of the Indian Premier League season due to a knee injury.
Malinga picked up what was described as a "bone bruise" when representing Sri Lanka in the 14-run Asia Cup victory over United Arab Emirates in February.
The fast bowler subsequently played no further part in the competition and sat out the World Twenty20, handing over the captaincy to Angelo Mathews as a result.
Ponting has concerns about the availability of Malinga - the highest wicket-taker in IPL history - but is confident in his back-up options.
"I believe he will be joining us after the first couple of games to have his fitness assessed. Right now it's unlikely he will take part in the first half of the tournament anyway," said Ponting.
"If we need a replacement, it will have to be named ahead of the fifth game. At this stage you have to say it is unlikely [that Malinga will play].
"Malinga at his best has been one of the great performers in world cricket, both with new and old ball. He will be missed, but we have to think about who the best replacement will be.
"Will it be Marchant de Lange, will it be Tim Southee? If Malinga is ruled out, we have more than adequate replacement to fill his boots."
Defending champions Mumbai take on Rising Pune Supergiants at the Wankhede Stadium in the tournament's opening match on Saturday.