Champion Hayden shoulders the pain

MotoGP world champion Nicky Hayden is to undergo surgery on a shoulder injury.

The Repsol Honda rider sustained the injury during a crash in the penultimate race of the season in Estoril.

But the American rode through the pain barrier to secure his maiden championship title in the final race in Valencia.

Hayden will be forced to miss Honda's next test session in Jerez but team-mate Danny Pedrosa could take part despite undergoing a minor arm operation.

Hayden said: "I'm flying back to the States tomorrow for Thanksgiving and to have some work done on my shoulder.

"I was carrying the injury into the Valencia race but the adrenalin got me through. But I've tried it out since and it just isn't right."