Rossi: next four races are crucial

Stoner's third place at Le Mans on Sunday extended his lead over Rossi to 21 points, as the Italian struggled with tyre issues and fell to sixth.

Rossi said his previous form at Mugello, Barcelona, Donington Park and Assen, the venues for the forthcoming races, made him optimistic.

"Those are four Grands Prix I enjoy very much, and where I've had some nice victories in the past," he told Gazzetta dello Sport.

"It will be important to do well, it's a crucial time in a very long season."

He added that it would be tough to regain the ground lost to Stoner, who has dominated on the faster tracks and still managed top four results on tighter circuits, and that Honda's Dani Pedrosa would still pose a threat.

"Stoner has been competitive at all times in every condition, so it will be difficult to fight against him," Rossi said.

"But I don't consider Pedrosa ruled out of the fight: here Honda weren't going badly, and they aren't so far behind in the championship.

"We must improve and try to put Casey under pressure a bit. It's not easy: the Ducati has shown to be competitive on slow tracks too."