The Shiv Sena threats not to allow the Australian cricketers to play over the racial attacks in Australia on Indian students caused quite a security scare for a few players. While Cricket Australia have left the decision to the players, the players themselves are looking for an official assurance.

Even as some of the IPL franchisees are understood to have told their Australian cricketers to stay back if they are afraid, Cricket Australia (CA) has left to up to the individuals to make their own call.
While there were initial reports that the Hyderabad Deccan Chargers captain, former Australian vice captain and wicket keeper, Adam Gilchrist, were seriously considering pulling out of the IPL 3 over the threats, his manager states otherwise. And Matthew Hayden who plays for the Chennai Super Kings believes that the security arrangements will be confirmed with CA and if CA is okay, the players are willing to go by the assurance.
Australian Participation in IPL in Trouble over Security Concerns
Shiv Sena Fires Fresh Salvo to Australian Cricketers Over Racism in Australia