Valentino Rossi refused to fuel rumours that Ducati could switch from its carbon fibre chassis to a more conventional aluminium design.

Aluminium twin-spar frames are used by all of Ducatis MotoGP rivals.

"I don't know," replied Rossi, when asked if he might try an aluminium frame this year.

"I know that we speak a lot to try to fix - try to improve - this bike and I know in Ducati they work.

"But I don't know exactly about [an] aluminium frame or some other things, and especially when. So we have to wait."

Seven time MotoGP champion Rossi, who won 79 premier-class races with aluminium twin-spar frames at Honda and Yamaha, is struggling for front-end feel with the Desmosedici.

The Italian has taken just one podium so far this year, but is still the top Ducati rider in the championship, in fifth.

The Desmosedici is unique in both its extensive structural use of carbon fibre and because the engine is employed as a stressed member - and not simply carried within the frame.

Rossi switched from the original GP11 to the modified GP11.1 motorcycle at Assen (round seven), based on next year's 1000cc bike.

All other Ducati riders are still using the GP11.

The Ducati Desmosedici used a steel trellis frame, as also used on Ducati Superbikes, from 2003 to 2009.