Marlboro Ducati's Casey Stoner could be ruled out of MotoGP's testing sessions at the end of the year as his improperly-healed wrist is giving him more problems than he likes to let on - and if it doesn't get better, he may miss the end of the season too.

Stoner, who was suffering from the injured scaphoid at Indianapolis, says he definitely needs an operation on his wrist but is going to wait for a couple of weeks to see if there is any improvement before making a decision on surgery.

Team boss Livio Suppo added that if the pain in manageable during a race then chances are the Aussie will finish the season but miss the Jerez test session. However, he went on to say that is no big drama as Stoner doesn't need a lot of test time on the GP9 anyway.