Sebastien Vettel will replace Kubica in US GP

The doctors disagreed with Robert Kubica and disallowed him from competing in the US Grand Prix, giving newcomer Sebastien Vettel his chance for hisfirst ever Formula One race.

Formula One driver Robert Kubica came to Indianapolis Motor Speedway proclaiming he was alert, clear-minded and ready to race Sunday in the U.S. Grand Prix.

FIA, the international governing body of racing, ruled Kubica could not yet climb back into the cockpit four days after sustaining a concussion and spraining an ankle in a frightening crash at Montreal. He will be replaced by Germany's Sebastian Vettel, a test driver for BMW Sauber.

"I felt absolutely ready to race," Kubica said in a statement issued by the team after the doctors' decision. "I respect the decision. It was made because there is too much risk to let me race in this Grand Prix in case I have an impact so soon after Montreal. I will go home now."

Vettel, a 19-year-old rookie, is expected to make his first F1 start Sunday.