Repsol Honda's Casey Stoner this afternoon admitted his tilt at retaining the MotoGP World Championship is over.

Doctors have advised the Australian to go home and have surgery on the ankle he damaged in a massive qualifying highside at Indianapolis and he looks set to miss at least three rounds, effectively handing the title to team-mate Dani Pedrosa or, more likely, Yamaha's Jorge Lorenzo.

"The plan is to get back to Australia as soon as possible because, after travelling, we have to wait for the inflammation to go down before we can have surgery. We already have everything lined up, hopefully for early next week if the inflammation has come down enough. The we will get on the road to recovery and see how quickly we can be back," said Stoner, speaking at Brno.

"I've done about as much damage as I can do down there. My doctor is very honest with things. Normally, he has no problem with getting back out there and me riding on injuries. Every piece of advice we have seen has said to get off this foot as soon as possible because If I damaged it again, it could be permanent and cause a lot of issues.

"The plan is to come back maybe a race or two before Phillip Island but until we have the surgery we really can't say exactly when we will be able to return. We will have to see how it goes and it could be a lot sooner than we think. I have a timeline in my head but it might not necessarily agree with the doctors' so we will have to wait.

"We had a good opportunity to get some points back at Indianapolis but this has finished our championship at this point. It's disappointing when you go this far into a championship and put in this much effort. We were coming to a point in the season to circuits that suit me better. To have this, especially in my last year, is frustrating. It's a big hit to the heart, that is for sure."