Rossi contemplates future

Former MotoGP world championship winner Valentino Rossi says his future in the competition is uncertain after his current contract with Yamaha expires in 2008.

The Italian rider said he was keeping his options open for beyond the 2008 season and will only continue racing MotoGP bikes if he can be motivated by fresh challenges.

"We'll need to find new motivations because we've already won everything," Rossi, a five-time world champion, told Italian newspaper Gazzetta dello Sport.

"I could also quit. I'm 28, I'm not too old, but I'll be able to go on until I'm 31 or 32 at most."

Indeed, Rossi is facing one of the toughest challenges in his career this season as his place at the top of the MotoGP tree has been routinely challenged by Australian world championship leader Casey Stoner on his powerful Ducati GP7 bike.

The two riders have engaged in some classic head-to-head battles this season that has seen Stoner pip Rossi to win the MotoGP at Catalunya before Rossi returned the favor at Assen in The Netherlands last round.

Rossi, though, has also previously spoken about wanting to ride for Ducati but says he is now quite comfortable racing for the Yamaha team.

"In the past I was tempted to move to Ducati because of the big adventure that it seemed… (having) an Italian rider on an Italian bike," he told MotoGP.com.

"But there is no reason to change if you're already at home in a team."