`` For me it 's very difficult to understand where the news starts because I never speak about my retirement , '' the 33-year-old said . Two - time MotoGP world champion Casey Stoner to retire at the end of this season . The Australian says he no longer enjoys the motorsport as much as he did . The American rider will practice ahead of Sunday 's Le Mans Grand Prix in France . Two - time championship winner Alexander Rossi aims to stay in the sport for another two years .
Two - time MotoGP world champion Casey Stoner to retire at the end of this season . The Australian says he no longer enjoys the motorsport as much as he did . The American rider will practice ahead of Sunday 's Le Mans Grand Prix in France . Two - time championship winner Alexander Rossi aims to stay in the sport for another two years .