FIAT Yamaha has confirmed it will honour its agreement to field a replacement rider for Valentino Rossi from the Catalunya Grand Prix onwards, although it remains unclear as to whom it will be.

Sources from within Yamaha had already hinted that it would prefer to concentrate on the sole M1 of championship leader Jorge Lorenzo for the time being, but contractual obligations with Dorna stipulate it must field a full line-up of riders by the third race.

As such, Lin Jarvis says there will be a new rider to take Rossi's bike from the Catalunya Grand Prix on July 4th, but would not be drawn on who has been approached so far.

"Concerning the replacement rider - we have decided to field a replacement rider from the Catalunya Grand Prix on 4th July," he said. "We have chosen the Catalunya Grand Prix to respect our Team Participation obligations to the MotoGP championship and also to take time to select the most suitable rider and to make sure we're organised and well prepared for this new situation. At this moment I am unable to tell you who the rider will be because we have not yet made a definitive decision."

While there will be no two-man line-up for FIAT Yamaha at Silverstone nor Assen, Jarvis says he hopes an announcement will be made shortly.

"We expect to be able to inform you of our plan next week or at the latest at the Silverstone MotoGP event."

From within the Yamaha stable, the likes of Colin Edwards, James Toseland and Cal Crutchlow have been mentioned as potential replacements for Rossi.

The anticipated preferred choice of Ben Spies is believed to be unable to make the switch by virtue of his 'rookie' status, one that prevents from riding a factory-backed bike in 2010.