Ducati's Casey Stoner is coming to the United States having won the last three races of the MotoGP calendar from pole position. However, the reigning series' champion believes that next weekend race in Laguna Seca won't be that easy for him and the Ducati team.

The Australian rider is now 20 points behind championship leader Valentino Rossi and he has put himself back into the championship battle.

Speaking of Rossi, the Fiat Yamaha star says that he will have to improve on his last qualifying performances if he wants to maintain his lead atop the championship. Rossi finished second to Stoner in Germany after starting from seventh place on the grid.

Meanwhile, AMA Superbike champion Ben Spies will be on the grid in Laguna Seca as a wild-card entry for Rizla Suzuki. The American made his MotoGP debut in place of the injured Loris Capirossi at Donington Park last month and is hoping for a good showing on a third Suzuki GSV-R.

Another American that will be happy to come back home is Colin Edwards who was lucky to escape uninjured a crash he suffered during the German Grand Prix at the Sachsenring. Up to the German round, Edwards had had a run of six-straight top-five finishes for Tech 3 Yamaha.

On his part, Repsol Honda's Dani Pedrosa will remain in hospital until at least tomorrow (Wednesday) while a decision is made on whether or not he can participate in this weekend's United States round.