Yamaha boss fears Rossi could walk away

Rossi was no match for Casey Stoner last year, finishing only third in the MotoGP riders' championship, and Brivio believes that the Japanese bike manufacturer cannot afford another campaign like that.

"Vale must decide what to do in 2009," Brivio said in an interview with Gazzetta dello Sport. "In my opinion, if we do as we did in 2007, he may even quit or do something else. We must recover, all together.

"That's why 2008 will be an extremely important year. For us at Yamaha, but also for the entire motorcycling world."

Brivio believes that as well as facing the continued threat from reigning champions Ducati in 2008, rivals Honda will join the title battle thanks to a renewed effort by Rossi's former tyre supplier Michelin.

"Because besides Pedrosa and Honda, there's Michelin," he said. "The French did not like the switch so they will multiply the efforts to beat us."

Brivio also denied speculation that he was poised to become Rossi's manager in the wake of the Italian's split with Gibo Badioli last year.

"Now Vale is doing that himself," Brivio said when asked about Rossi's management situation. "We at Yamaha are supporting him for logistics, travelling and communication.

"In 2008 I'm a Yamaha team manager and, at the moment, I'm busy and focused on this role."

Fiat Yamaha are unveiling their new bike at the Giovanni Agnelli Auditorium in Turin today, with Brivio confirming that once again in 2008 the bikes will run with special liveries in certain races.