Rossi has been with Michelin ever since his 2000 premier-class debut and won the 500cc/MotoGP title five times with the French manufacturer from 2001-2005. However, chatter problems during 2006 and especially the dominance of Bridgestone in 2007 has seen the relationship rapidly cool.

This season saw Michelin lose the MotoGP title for the first time since 1991 and rumours soon surfaced that Yamaha star Rossi (like Honda's Dani Pedrosa) was pushing hard for Bridgestone tyres - as used by new MotoGP world champion Casey Stoner - in 2008.

When those requests were initially turned down by Bridgestone, MotoGP faced the possibility of a single tyre rule being introduced, but a compromise was subsequently reached to keep tyre competition alive.

As part of that compromise, Rossi will now get Bridgestone tyres, but be the only Yamaha rider on the Japanese rubber, since new team-mate Jorge Lorenzo (plus Tech 3 riders Colin Edwards and James Toseland) will use Michelins. Pedrosa and Repsol Honda team-mate Nicky Hayden will also keep the French brand.

"In order to facilitate the use of both Michelin tyres and Bridgestone tyres within the Yamaha Factory Team and to ensure confidentiality of data for each tyre company, Yamaha will organise separate rider pit boxes [with a team manager for each rider], but the Fiat Yamaha Team will continue to operate and race as one team," said a Yamaha statement.

Rossi's triple hand fracture - sustained at Valencia on Saturday - and Yamaha's existing contract with Michelin mean that the Italian's Bridgestone debut will have to wait until the end of this month.

Meanwhile, it was also confirmed that Ramon Forcada, most recently crew chief for Carlos Checa, will fulfil that role for reigning double 250cc world champion Lorenzo during his debut MotoGP season.

Click on the third picture below to see Fiat Yamaha's full 2008 team structure.