Updated: Rossi slow, slams track safety.

Reigning world champion and runaway 2005 world championship leader Valentino Rossi was left in an uncharacteristic ninth place at the end of day one at the US GP, having failed to improve in the afternoon session.

The Italian superstar would later reveal that he had been struggling to adapt to the 'old style' layout of the Laguna Seca circuit - presumably meaning how to attack the narrow, bumpy asphalt with its many ups and downs, but reduced run-off - and wasn't riding at the limit.

"This is an 'old style' track and to be honest I think maybe our bike is a little too fast for it, so today I haven't been able to push to the limit," said Rossi, who lapped 0.74secs slower than pace setter Nicky Hayden. "When you're walking around it or going around it on a scooter, it's actually even more dangerous than when you're on the motorbike, when it feels safer!

"It is hard to find the right set-up in these circumstances and at the moment we still have a lot work to do. We need more time on the track and more kilometres with the bike to find out where we can push harder, make up some time and be stronger."

Rossi's comments seemed to suggest that safety concerns were preventing him from riding at his M1's full potential - and the #46 would admit that he, like many others, is worried about safety at the spectacular race track... to the point where he feels MotoGP may not be able to return.

"The level of security (safety) is not very good, it's not as good as the other tracks we race at. If we don't make some changes to this track for the future we may not be able to race here again," he warned.

"However, today (Friday) we will have a meeting with all the riders to speak about the problems. I never saw this track before but Kenny Roberts saw it and obviously thought it was safe enough," said Valentino.

"Anyway, I have enjoyed riding at Laguna Seca, especially the Corkscrew, because in the past I have only seen it on the television. The big crowds here show that MotoGP should be in America, but we also need to make sure it is safe," he concluded.

However, the only man to have ridden both a 500cc and MotoGP machine around Laguna Seca, Camel Honda's Alex Barros, disagreed with the world champion. The Brazilian felt the track was safe enough and that the only changes he would like would be to smooth the bumps at turn one and around the corkscrew.

Barros, speaking to Crash.net's 'Press Snoop' Lynne Huntting, called the circuit layout "fantastic" and added that: "Riders should make (safety) suggestions, for next year. Not demand that changes be immediately made or the riders won't race. Riders must respect all the efforts which have been made to bring MotoGP to America."

The top six riders at Laguna Seca on Friday - Hayden, Bayliss, Biaggi, Barros, Hopkins and Edwards - had all ridden at the circuit before. The top 'rookie' was Movistar Honda's Sete Gibernau.