Stoner: Retaining title nearly impossible

Stoner had fought back after a difficult start to the season, winning four consecutive races and finishing second to Rossi at the United States Grand Prix.

But the Ducati rider made a rare mistake in the last race in Brno and crashed, handing Rossi a 50-point lead with six races remaining.

Stoner reckons catching the Italian will be almost impossible.

"We have six races to go and these are the ones we have to look at now," Stoner told a news conference at Misano. "It has been a disappointing couple of races, mainly the last one.

"It's given Valentino a huge gap in the championship and it's just time for us to keep our heads down and try to do the best we can in these last races. We have nothing more to do other than this.

"I think chasing a championship down with this points gap is maybe possible with other riders, but with Valentino is nearly impossible."

He added: "We have to do the best job we can. We found some positive points in the Brno test. We have a little more confidence with the bike and hopefully we won't make a mistake like last week.

"But considering we've done 30 races with Ducati and this was my first crash in a race, so I think it's acceptable."

Despite the pessimism about his championship chances, Stoner is expecting to enjoy a strong race at Misano this weekend.

"Last year was a good race for us and we'll see what happens this year. But we seem to perform well here, so we'll just have to see."