Ducati will take the first step towards toning down the radical design of its Desmosedici MotoGP machine, when Valentino Rossi swaps carbon fibre for an aluminium front-section during this weekend's Aragon round.

The seven-time MotoGP champion, who is sixth in the world championship with just one podium from his 13 races for Ducati, will have one bike fitted with aluminium after a positive test with the material on the 2012 bike at Mugello last week.

But Rossi made clear that Ducati isn't abandoning its stressed-member concept, which sees the engine used as part of the frame.

"It's not [an aluminium] frame," Rossi clarified. "The [stressed engine] philosophy of Ducati remains the same. The front part of the bike is a bit different and is aluminium and not carbon fibre like it was before."

The Doctor claimed that the change has been made in order to speed up development of the GP11, since aluminium can be modified more quickly.

"It's a question of time with regards to the material," he said. "We have to work, to try to understand, and with aluminium we need a lot less time than the carbon."

That opens the door for a potential carbon fibre return, once the correct flex has been identified using the aluminium, but after such a tough season many doubt that Rossi will want to change back.

"It's just the first step, we'll keep working and we'll try to come back and fight for the front positions," Rossi added.

Ducati took a low-tech frame approach for its race-winning 2003 debut MotoGP season, utilising the same kind of steel trellis design used in its Superbikes, but has made a series of big changes since.

First the Ducati engine became 'stressed' and by 2009 the Desmosedici was using carbon fibre for both the front airbox section and rear swingarm.

But while carbon fibre is, in theory, more adjustable in terms of creating the desired flexibility than aluminium, only Casey Stoner has been able to achieve success with the bike.

With Rossi and his team of mechanics also struggling to make clear progress, Ducati seems to be heading towards something closer to the (unstressed) twin-spar aluminium frames used by all its MotoGP rivals.

It is those kind frames with which Rossi has won a record 79 MotoGP races for Honda and Yamaha - and his mechanics have so much experience of working with.

Ducati briefly tested an aluminium airbox section before opting for carbon fibre. At the time there was said to be little difference, and so Ducati went with the futuristic material.

However Rossi preferred the feel of the aluminium when testing next year's 1000cc bike at Mugello last week, and hopes that the material change will have a similarly positive effect on this year's 800cc bike.

The 2011 Ducati has already undergone one major design upgrade during the racing season, with an 11.1 version - featuring a modified chassis and gearbox - being introduced for Rossi at Assen.

Rossi's main problem, like that of many 800cc Ducati riders, has been a lack of front end feel.

Team-mate Nicky Hayden is not expected to get the revised chassis and will continue with the GP11.1.