MotoGP world champion Casey Stoner hopes his former employer Ducati can produce a more consistent challenge in 2012 - especially with the number of works bikes at the front of the field shrinking.

Ducati has not won a race since 2010, as Stoner's Honda team and Yamaha dominated last season. Over the winter Suzuki withdrew its remaining MotoGP entry and Honda's works team scaled back from three to two bikes, potentially leaving just four potential race-winning bikes at the front of the field if Ducati struggles again.

Stoner is sceptical about Ducati's chances of turning its form around in time for the start of the 2012 campaign, but says he hopes to be proved wrong as he feels MotoGP needs a third manufacturer fighting at the front.

"Ducati are saying that they completely revamped 90 per cent of the bike, but they did that in the middle of last year," Stoner told the official MotoGP website. "They changed the bike back to front and top to bottom and nothing much changed.

"I'm hoping, for Ducati's sake, that they can put together a competitive bike this year because the championship needs it.

"Regardless of what the riders want, everyone needs as many manufacturers at the front as possible. Yamaha and Honda want competition; unfortunately Kawasaki and Suzuki are gone from the championship, so we need all bikes at the front."

The Australian tipped 2010 champion and Yamaha number one Jorge Lorenzo as his main opposition this season, and also tipped ex-Honda rider Andrea Dovizioso to impress in his new surroundings at Tech 3 Yamaha.

"My main rival will be Jorge, he was first in 2010 and second in 2011, he will always be there fighting," said Stoner. "All the factory guys as well as Andrea will be pushing up there on the Tech 3 Yamaha, it's the same crew as in the past.

"Unfortunately we will be missing Marco [Simoncelli], who I'm sure would have been up at the front. Year by year it changes, so we will see who can put it together for the whole season."

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