Repsol Honda's Casey Stoner says that nine-time world champion Valentino Rossi is forced to fight for results now and can no longer fight and play with the competition before clearing off in the final laps of MotoGP races.

Stoner, who is leading the 2011 series by 44 points from reigning champion Jorge Lorenzo, thinks the skill level of riders has now got to the point where The Doctor has to fight for every result and can't just cat and mouse his way to wins like he has in the past.

"There is no way Valentino fights and plays anymore, he hasn't been since we have been racing against him. He doesn't fight, he doesn't play, he goes out to try and win. He is good at holding on to people who are a little bit faster and being able to tail them, then put last minute moves on but we've all learned how to do that so it's not something that he is any better than us at," said Stoner, speaking to bikesportnews.com.

"It's evidence that in the past he could play with the riders and then beat them in the last few laps but now he doesn't try any of that stuff. He is there pushing every step of the way. If he can make a gap he does and if he can't he fights, which is something he is very good at."