Repsol Honda has announced that Casey Stoner will leave Brno this evening for Australia, after his doctors advised him to have surgery on his damaged ankle.
Stoner sustained numerous right ankle injuries - including torn ligaments and small fractures to his ankle, tibia and fibula - during a huge qualifying highside at Indianapolis last Saturday.
The Australian bravely returned on Sunday where he rose as high as third in the race, before his weakened physical state allowed Andrea Dovizioso to seize the final podium position.
Stoner, the reigning MotoGP champion who will retire at the end of 2012, has already slipped 39-points behind Yamaha's title leader Jorge Lorenzo with seven rounds to go.
Stoner's medical team in Australia had been reviewing the results of an MRI scan and his last-minute withdraw from this weekend's Czech Republic round means that his hopes of a third MotoGP title are surely over.
Stoner will also miss out on Monday's post-race test.
Round 13 of 18 will be held at Misano from September 14-16.
Stoner's team-mate Dani Pedrosa starts this weekend's Brno round 18 points behind Lorenzo.