Reigning six-time MotoGP world champion Valentino Rossi insists that his enthusiasm is as high as ever heading into the 2009 season, his 14th year in grand prix racing and tenth in the premier-class.

"My excitement at the first race is the same as 1996; when this feeling changes then it is time to stay at home," said the Fiat Yamaha rider, ahead of this weekend's Qatar season-opener.

But whilst Rossi's motivation remains undiminished, he admits that the on-track excitement has been reduced since the switch to 800cc engines for 2007.

"I think we lost a lot of the show when we made the switch from 990c to 800 bikes," he said. "The type of races are different now... This season we have the same tyres and maybe the situation in the races will be more clear and I hope more exciting for everybody."

In terms of his closest rivals, Rossi unsurprisingly picked 2007 world champion and 2008 runner-up Casey Stoner as the man to watch this weekend.

"Casey is very fast at all the tracks and especially here in Qatar. He has won the last two races here so he will be very strong for sure," said Rossi. "During testing my team-mate Lorenzo was fast more or less everywhere. Now we have to wait and see the condition of Dani [Pedrosa] to understand his level."

Rossi is now just three race wins away from 100 grand prix victories.