MotoGP champion Marquez defends Zarco's move on Rossi at Austin

Rossi said Zarco - title winner in the intermediate class in 2015/16 - had to realise "this is not Moto2" and argued he made his passing attempts too late.

The comments followed an incident at Austin for which works Yamaha rider Rossi was given a 0.3-second corner-cutting penalty after going off-track following a touch with Tech3 man Zarco as they fought for third.

Marquez reckoned Zarco had not done anything he or Rossi would not.

"Of course it was aggressive, but in the beginning everybody is pushing 100%," said Marquez of Zarco's move.

"I'm an aggressive rider, Valentino is an aggressive rider, we also overtook really strongly in the past, and we will again in the future.

"If you are aggressive and you overtake strongly, you need to understand the other riders are also aggressive. It's always like this, it's racing."

Rossi finished second despite his penalty, which Marquez agreed was an unnecessary punishment as "he didn't gain anything" by missing the corner.

Zarco slipped back to an eventual fifth place after a late battle with Cal Crutchlow.

While acknowledging that Zarco's "bike's a rocket because he's really light and he's got a lot of grip", Crutchlow praised the rookie's performances.

"He's really aggressive on the first lap - really aggressive anyway - which is good," said Crutchlow.

"I don't see anything particularly wrong with it.

"It's a little bit different in MotoGP to Moto2, but we give as good as we get.

"In the end, he rode a good race as well. You have to give him credit."

Austin third-place finisher Dani Pedrosa suggested Zarco was just adapting to how to race closely with a MotoGP bike compared to Moto2, rather than being deliberately over-assertive.

"I don't know if it's related to the class or not," said Pedrosa when asked if he felt Moto2 riders were more aggressive.

"My experience when I changed to MotoGP was when you adapt to the weight and the speed, everything happens at different timing - the chicanes, the braking.

"You arrive much faster and the weight is much more, the space is much less, the riders are much better.

"You need to figure out all these timings, and of course in the beginning you have a different approach to these moments."