Preview - Italian Grand Prix.

If Valentino Rossi was to select a particular event to restart his championship campaign it would surely be his home Italian Grand Prix at the magnificent Mugello circuit.

The Italian Grand Prix is one of the great motorsport events of the year: The 3.259 mile Mugello circuit intrusively winding between the gentle contours of the stunning Tuscan hills with the patriotic crowd producing a passion that is rarely matched anywhere in the world.

But world champion Rossi arrives home in a desperate position. After five rounds of the MotoGP World Championship he trails leader Nicky Hayden by a massive 43 points, down in eighth place after a series of misfortunes that have tested his temperament to the very limit.

Two weeks ago he looked certain to win the French Grand Prix at Le Mans when he was forced to stop while leading with a mechanical problem on his Camel Yamaha. However, up until then it appeared that Yamaha had cured the handling problem that had dogged both Rossi and team-mate Colin Edwards with a new frame and both face the 23 lap race on Sunday with great confidence.

Rossi has won the race for the last four years for both Honda and Yamaha after some epic all Italian battles that have sent the crowd wild and the television ratings through the ceiling - and another home 'Doctor' victory would be the perfect way to celebrate his brand new 2007 Yamaha contract.

It was Italian Marco Melandri that took full advantage of Rossi's misfortune to win his second grand prix of the year. Riding the Fortuna Honda, he moved into joint second place in the championship with veteran Loris Capirossi, who was a brilliant second on the Marlboro Ducati in France. The former 125 and 250cc World Champion won the 500cc race at Mugello six years ago and a victory by Capirossi for home manufacturer Ducati would send Italy wild.

The pair trail Hayden by just two points, but will be looking over their shoulders for the young guns to appear. Both 250cc World Champion Dani Pedrosa and Australian Casey Stoner have rattled their established stars to the core in their debut seasons. Twenty year old Pedrosa started the last two races from pole position on the Repsol Honda and finished with a win in China and a third place in France. He trails Melandri and Capirossi by just six points going into just his sixth MotoGP race. Twenty year old Stoner has been equally impressive on the LCR Honda and is just eight points behind his great 250cc rival Pedrosa. Neither rider has a particularly good record at Mugello though, with Pedrosa securing the only win in the 250cc race last year.

Another former 250cc Mugello winner, Shinya Nakano, returns to the circuit where he walked away from a 215mph accident two years ago. The Japanese rider has had a tough opening to the season on the Kawasaki, culminating in a ride-through penalty for jumping the start at Le Mans where his team-mate Randy de Puniet crashed at the first bend.

American John Hopkins crashed out of a potential podium finish at Le Mans after being forced to override his Suzuki to keep up with Rossi and Pedrosa, but he and his GSV-R are becoming an ever bigger threat - having started the French race from the front row and finished fourth in China.

Rookie team-mate Chris Vermeulen, who took a wet pole at Istanbul, will continues his MotoGP education this weekend, while Konica Minolta Honda's former race winner Makoto Tamada has been improving in recent races - but Spaniard Sete Gibernau could slip under the radar and spring the biggest surprise during his first Italian Grand Prix for Ducati.

Meanwhile, in the 250cc class, Andre Dovizioso is probably approaching Mugello in a similar way to countryman Rossi. The Italian 250cc championship leader looked likely to win his first 250cc grand prix last time out at Le Mans, only for his Humangest Honda team-mate Yuki Takahashi beat him to the chequered flag. Dovi leads Spaniard Hector Barbera by 14 points in the championship - and what better place for the former 125cc World Champion to break his duck than in front of his home crowd?

Barbera's Fortuna Aprilia team-mate Spaniard Jorge Lorenzo won the opening two rounds but crashes in Turkey and Le Mans have pushed him down to fifth place behind Takahashi and the impressive Hiroshi Aoyama - who's giving KTM a fantastic first season in the class.

But the real dark horse could be veteran Roberto Locatelli who's hit tremendous form riding the Team Toth Aprilia and has a record second only to Rossi at the circuit - which is just a couple of miles from his home. He has won the 125cc race three times at Mugello and is very capable of making it four with a 250cc victory.

Despite mechanical problems on the last lap in Le Mans, Spaniard Alvaro Bautista still has a 21 point lead in the 125cc championship over the KTM of Finnish rider Mika Kallio. The race in France signaled the return to form for World Champion Thomas Luthi who was a comfortable winner - but the already difficult defence of his world title took a further massive blow when he broke his collarbone while testing last week.