Marlboro Ducati's Nicky Hayden has taken the decision to undergo surgery on his damaged shoulder in California tomorrow after the Sepang MotoGP tests uncovered the injuries he sustained in a flat-track accident last month were more serious than first thought.

Hayden was unable to put in any meaningful times over the three days in Malaysia and, after going home, flew to Dr Ting's clinic in Fremont. Scans showed not only is there cartilage damage in the shoulder but also in the Kentucky rider's back musculature as well. It is not yet known how long it will take Hayden to recover but he could be in serious doubt for the second Sepang tests at the end of this month.

“Of course another operation before the season is never a good thing but I’m actually happy that I tried to ride at Malaysia, because it helped me to discover that the problem with the shoulder was bigger than we thought. After seeing the scans, it was clear why I couldn’t ride well," he said.

"Setbacks are a part of life and a part of MotoGP, so we’ll deal with it and do everything possible to get back on the bike in good condition as soon as possible. Ducati and the team are putting maximum effort into this championship, and that helps me to keep my spirits high and to be confident heading into the season.”