World motorcycle champion Casey Stoner will miss this weekend's Czech Grand Prix after heading home to Australia to undergo surgery on his broken ankle and admits his title defence is virtually over.
The Honda rider fractured his right ankle in qualifying for last weekend's Indianapolis Grand Prix although he decided to race and finished fourth.
But Stoner says his doctors have advised him to have surgery on his damaged ankle to avoid any permanent injury.
Stoner, who will retire at the end of the season, is third in the world championship standings after 11 races, 39 points behind series leader Jorge Lorenzo.
Ducati's Nicky Hayden will also miss Monday's race in Brno after suffering a hand injury during qualifying last weekend.