Ducati's Nicky Hayden has been ruled out of this weekend's Brno MotoGP round after the injuries he suffered in a big crash at Indianapolis have left him with a very swollen right hand and a lack of strength.

Hayden was spat off his Desmosedici on the same part of the track at Casey Stoner and Ben Spies but he was knocked out and declared unfit in America. He has realised he isn't in 100 per cent conditions so has withdrawn from action in the Czech Republic.

“It’s tough to miss another race. I don’t have big problems, but my hand is still very swollen and I don’t have much strength, and of course right-hand injuries are worse for motorcycle racers. I would have been at far less than 100 per cent, and if I used too much force or crashed again, I could displace the breaks and possibly be in big trouble," said Hayden.

"Obviously, the head is even more important, and with the amount of time I was unconscious, I’m still dealing with a headache. The main thing is all the doctors told me racing was a really bad idea and not smart, and everybody on my team agreed. As much as the racer in me doesn’t like staying at home and missing track time and points, I need to listen to the experts and try to heal up and get ready for Misano. That’s an important race for me and for Ducati, and I’ll be doing all the rehab to come back as fit as possible. I don’t like it, but it’s the right thing to do.”