The BoyleSports Irish Greyhound Derby has been thrown wide open after hot favourite Clares Rocket sustained a wrist injury.
The injury, which was sustained in Shelbourne Park last Saturday, has forced the trainer to retire the dog to stud.
Clares Rocket was kidnapped earlier in the year before being returned.
Trainer Graham Holland told the Racing Post: "I was afraid there might be a problem when he appeared to check going into the first bend on Saturday and then again at the third bend.
"He was then caught close home which is not his style. Those fears have been realised and the dog will probably never run again."
Sonic is the new favourite following Clare Rocket’s withdrawal.
The Derby semi-final and final will be broadcast on RTÉ2 over the next two weekends.