"I'm really disappointed because I felt in the race that I had the pace to at least pass Hopkins and Edwards, so as far as I am concerned we have lost 16 points and a podium, which would have been a good result after the problems we've had this weekend," he added. "We've lost some ground in the championship so I am feeling very disappointed right now but there is a long way to go yet."
Rossi was using exactly the same wider-profile front tyre as all but one of the other eight Michelin riders, but was the only person to suffer such a problem - the cause of which will now be investigated by Michelin.
"Valentino was doing a good job, aiming for the podium, then he started feeling some vibration that was big enough to bring him into the pits," confirmed Michelin motorcycle racing director Nicolas Goubert. "Unfortunately the vibration was created by the front tyre, which we will take back to France to undergo analysis at Clermont-Ferrand (on Monday) morning. It is very strange because he chose exactly the same front as all but one of our nine riders. Only Kenny Roberts Junior chose a different front, a slightly harder compound and construction."
Meanwhile, Camel Yamaha team director Davide Brivio put the problem down to bad luck - and added that it wouldn't have mattered if the team had spotted the missing front fender/tyre damage during the pit stop.
"Valentino had a bad day, and even if we had changed the front tyre the first time he came in, it would have taken too long and the race would have already been lost," he said. "He has been very unlucky this year - firstly with the incident in the first corner at Jerez and now this time with the tyre. It's always upsetting when your results are decided by things that are out of your control but there is nothing he can do about it, only look forward to making up for lost ground over an important run of races in the next few weeks."
Rossi has now slipped to sixth in the 2006 MotoGP World Championship standings, a worrying 32-points behind Repsol Honda's Nicky Hayden.
