Davide Brivio, Valentino Rossi's team manager throughout his Yamaha career, has given an insight into the seven time MotoGP champion's switch to Ducati.

Rossi joined Yamaha, from Honda, as the reigning triple world champion at the end of 2003. It was a huge gamble, given that the M1 motorcycle took just one podium in the season before Rossi's arrival.

But the Italian, crew chief Jerry Burgess and Yamaha boss Masao Furusawa transformed the M1 over the winter. Rossi won the very first race of 2004, and ultimately Yamaha's first MotoGP title since 1992.

Rossi defended his crown in 2005, then bounced back from two successive title defeats to win again in 2008 and 2009. His 2010 title hopes ended with a broken leg at round four, while trailing team-mate and eventual champion Jorge Lorenzo in the points.

Despite Lorenzo's ascent, the Rossi/Yamaha relationship had been expected to continue, but Brivio believes Yamaha no longer felt dependent on Rossi for success.

"In 2003 when Valentino decided to come to Yamaha, Yamaha desperately needed Valentino," said Brivio. "But now Yamaha have Lorenzo and Spies, the other riders who can win with Yamaha.

"Yamaha wanted Valentino to stay, but also prepared without him.

"At the same time, Ducati wanted Valentino desperately - like Yamaha in 2003. Ducati and Rossi, they're Italian so they also understand each other."

And can Rossi repeat his Yamaha glory at Ducati?

"It is not an easy challenge because the rivals are very strong. But from technical point of view, maybe it will be easier than 2004 when Valentino came to Yamaha," said Brivio.

"The Yamaha in 2003 was not a winning machine and now Valentino will join Ducati, which already has a very competitive bike. It is already a winning machine.

"Valentino will have new challenge and will put a lot of motivation into this competition.

"I think he will fight for the title.

"It will be interesting to see Valentino and Jorge on different bikes. They have fought with the same bike and let's see how they fight with different bikes."

Lorenzo secured the 2010 title at Sepang last Sunday, when Rossi won his 46th race for Yamaha - his first victory since round one at Qatar.

But Qatar was the only race this year that Rossi has started at full fitness, having suffered a shoulder injury on a motocross bike shortly afterwards.

"This year has been very difficult because Valentino only raced in Qatar, the first round, with 100 percent physical condition," confirmed Brivio. "After the shoulder injury and crash in Mugello, he's never raced at 100 percent."

Rumours suggested the shoulder injury was so bad that Rossi might not even finish his final Yamaha season, but his strong form at Motegi and then Sepang mean The Doctor won't head for surgery until after the Valencia finale.

"The target now is to finish the season and then have surgery. This is the plan," declared Brivio.

The timing of the surgery will partially depend on whether Yamaha agrees to let Rossi test for Ducati straight after the Valencia race. Rossi is under contract with the Japanese factory until the end of 2010.

"It is technical decision of Japanese engineering management," stated Brivio, regarding the Valencia test. "Furusawa, he is re-thinking and considering. Probably yes... but difficult, not 100 percent sure."

Brivio is also rumoured to be leaving Yamaha at the end of this season, to concentrate on rider management.