Rossi still fearful of Ducati's speed

The Italian was virtually unchallenged at Jerez after overtaking pole-setter Dani Pedrosa on the opening lap, as Qatar winner Casey Stoner found himself unable to fight for a podium after being bundled down the order early on.

But despite his own strong performance, and the fact Ducati could not exploit their top speed on the tight Spanish venue, Rossi has admitted that he is fearful about Yamaha's chances at the forthcoming races.

In fact, the next five races on the calendar - at Istanbul, Shanghai, Le Mans, Mugello and Barcelona - have some of the longest straights of the season, and that could lead to a repeat of what happened at Qatar, where Stoner was easily able to blast past Rossi on the straight to seal his victory.

"Yes, I am worried about the long straights on the tracks coming up," said Rossi. "The situation in Qatar was clear - the difference with the Ducati is big.

"There is a difference with the Honda, which is less although a bit too much, so we have to work and we need to speak a lot with the engineers.

"At Jerez the speed is not a big issue, but for the next races it is important. I am hoping to try something new in the test here this week."

Rossi admitted that the speed improvements that he feels Yamaha need to overcome Ducati's advantage will require more than just revised engine mapping strategies to cope with the new 21-litre fuel limit.

"We were a little bit conservative in Qatar, but I don't think we will arrive at the speed of Ducati by using the fuel left in the tank," he said. "It will help a little bit, but the difference is too much."

Yamaha are testing engine evolutions at today's test in Jerez, although team boss Davide Brivio has denied that they are a major overhaul in response to Ducati.

"These aren't things born after the Losail race: they are evolutions planned in the development program approved long ago," he told Gazzetta dello Sport.

"And anyway, they aren't big things: it's a new engine in the sense that we haven't worked on the electronics, but there are some new components inside. However, they are tiny differences. Maybe we'll gain one or two km/h in top speed, no more.

"In any case, this is certainly not a track where you can work out whether you've taken the right route. But the next circuits are very fast, so it can be useful in order to get a feeling on whether we can take these new bits to Istanbul, maybe for free practice."

Additional reporting by Michele Lostia.