Doohan: Rossi battle has helped Stoner

After winning three of the first four races of the season, Stoner has silenced all the doubters who criticised him for crashing too much during his junior career and his debut MotoGP campaign in 2006.

And Doohan has praised the job the young Australian is doing, thinking that his accidents were just part of a learning process that has resulted in him becoming such a strong competitor now

"His profile has increased because he's won some races, but he has served a long apprenticeship and people who follow our sport closely know this," Doohan was quoted as saying by the Herald Sun newspaper.

"Some people criticised Casey for crashing too much when he came into Grand Prix racing in the 125s and 250s. In reality, he was learning the limits of the bikes he was racing. Crashes are part of racing. I had my share of them, especially in my first season in 500s (1989).

"The challenge of going head-to-head with Valentino for the championship will bring out the best in Casey because there is a target for him to aim at."