Stoner re-opens broken bone.

Despite dominating both Friday practice sessions with a flawless opening day performance at Misano, Casey Stoner's San Marino Grand Prix hopes have been thrown into doubt by a freak wrist injury.

The reigning world champion finished the day a comfortable 0.418secs ahead of world championship leader Valentino Rossi - but somehow re-opened a broken scaphoid bone, damaged back in 2003, in the process.

"The scaphoid is a really strange one because there has been no impact on it," explained a surprised Stoner. "I was just adjusting my back protector before going out for one of my runs this afternoon and I felt some pain.

"It got worse as the session went on so we decided to check it out with the Clinica Mobile and I couldn't believe it when they showed me the x-ray - it seems the bone I broke in 2003 has re-opened."

The injury will make it extremely painful and awkward for Stoner to ride on Saturday, although the Australian will undergo physio and wear a special support in order to give it his best shot.

"It's not going to be easy and I'll have to take care not to cause any further damage but my plan is to compete tomorrow," confirmed the Ducati Marlboro rider. "It's a shame because other than that everything else went really well today.

"It's nice to get off to a good start at this circuit, we went well here last year and the bike and tyres seem to be working well already. Hopefully we can continue like this tomorrow," concluded Casey, currently 50 points behind Valentino Rossi after mistakes at the last two events.

Stoner won the 2007 San Marino Grand Prix from pole position.