American Nicky Hayden has suffered a series of injuries while training in the U.S.

Two of MotoGP’s biggest stars, Nicky Hayden and Andrea Dovizioso, have suffered frustrating pre-season injuries while training for the 2012 world championship.

Hayden’s winter vacation was marred on Tuesday, 27 December, when he broke his left scapula and fractured two ribs while training near his home in Owensboro, Kentucky.

Hayden was training at a private indoor flat track facility, riding a motorcycle for the first time since breaking his scaphoid at the Valencia Grand Prix on 6 November. He underwent an X-ray and CAT scan on the same day he was injured, and he has since undergone an MRI.

According to the healing process, the next few weeks will determine whether Hayden will take part in the first winter test session of 2012, which will begin on 31 January in Sepang, Malaysia.

“Obviously, injuries are never good,” Hayden said, “but it’s part of motorcycle racing. Just like at Valencia, it was kind of a freak accident. I was starting to train again, like I normally do during the winter, at a private track near my house.

“I came up behind another rider, and he went to move out of the way. I wasn’t going that fast, but he clipped my front wheel and I went down and landed pretty hard on my left shoulder, and that was it.

“It’s disappointing, but there’s nothing to do about it but heal quickly. Anyway, this doesn’t change my expectations for 2012 which, fortunately, is just around the corner.”

Hayden will be in attendance at Ducati’s annual WROOM team launch in Italy alongside Ferrari this week.

Meanwhile, new Tech 3 Yamaha signing Dovizioso suffered a broken collarbone while riding motocross at home in Italy early in the new year.

It’s reported that Dovi underwent surgery in Italy last week, expected to take part in the pre-season test at Sepang later this month.