The MotoGP champion, Casey Stoner, had to sit out the start of pre-season testing yesterday after pulling his back doing warm-up exercises at Malaysia's Sepang circuit.

But the Australian Repsol Honda rider, who chases a third title this year, was hopeful of riding today and explained: "I was stretching for a good 20 minutes preparing to go out for the first time and then all of a sudden my back just locked up on me. I couldn't move or do anything. I had to call someone to come and help me move into a position that was less painful."