Valentino Rossi, who can clinch his sixth MotoGP crown by finishing third or better in Sunday's Japanese Grand Prix, will have his first ride on an early version of the 2009 YZR-M1 at Motegi on Monday.
The test will be used to guide Yamaha's development of its third 800cc MotoGP machine and marks a repeat of last season, when Rossi evaluated an early version of this year's M1 straight after the 2007 Japanese event (pictured).
"Taking advantage of the opportunity that we have here in Japan, Yamaha wanted to get some initial feedback from Valentino on some parts that might be on the 2009 machine," Rossi's Fiat Yamaha team manager Davide Brivio told the official MotoGP website.
"We are busy with building the 2009 prototype that will be used during the winter test, starting from Valencia after the race. So it is a good opportunity for Valentino to give some comments and see whether the engineers are taking a good direction or not."
Currently Rossi is the only Yamaha rider on Bridgestone tyres, something that could change in 2009 with the rumoured introduction of a one tyre rule.
"The development is not for Bridgestone tyres, the development is to improve the bike in general," insisted Brivio. "We can say this  bike has been built on Michelin because that was the only information we had to base it on and it has been good on both Michelin and Bridgestone tyres, so that has to be the same for next year.
"We don't know what the tyre situation will be [for 2009]," Brivio added.
Ducati was the first manufacturer to publicly debut an early version of its 2009 MotoGP machine, world champion Casey Stoner riding an early version of the carbon-fibre framed GP9 during the post-race Catalunya test in early June.