Briton Leon Camier will stand in for Nicky Hayden on the Aspar Honda for the next two MotoGP rounds as the 2006 world champion recovers from wrist surgery.
Hayden has been plagued by an old wrist injury flaring up again during the first part of this season, and has already had to withdraw from June's Italian Grand Prix at Mugello because of it.
He had hoped that it could be resolved with surgery during the current break between the Sachsenring and Indianapolis rounds, but has now been advised to skip the Indy and Brno events to give himself time to fully recover.
World Superbike regular Camier had expected to contest the 2014 MotoGP season with Ioda, but its plans to field a second entry fell through.
The 27-year-old, who won the 2009 British Superbike title, was on standby to replace Hayden earlier in the year, and will now get the chance to make his MotoGP debut in the Indianapolis and Czech GPs.
Hayden is optimistic that his latest round of surgery will provide a permanent cure for the problem, which dates back to his first-lap crash in the 2011 season finale at Valencia.
"Sometimes it is difficult, but we know that injuries are part of our sport and we must learn to manage them," he said.
"Everyone knows that my wrist has been causing me problems, especially at recent races. I underwent an operation in June, which helped me to complete the first half of the season, but the truth is I've been riding with a lot of discomfort, and have been unable to perform at my best.
"So, together with the team, we decided to make an important decision and undergo a larger operation to treat an injury that comes from three years ago.
"According to the doctor my recovery is on course, which is very positive.
"It takes patience, but if I have made the decision to have surgery it is to get back to my best. I made the decision thinking about being healthy for the end of the season and already thinking about next year."
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