Rossi "surprised" to see all Yamahas fast in Misano

Rossi rode with a new carbon swingarm, brake cover and exhaust, all of them recently introduced by Yamaha, while his teammate Maverick Vinales stuck with the old material.

Vinales ended Friday's running fastest and Rossi was a promising fourth, with Petronas duo Fabio Quartararo and Franco Morbidelli also in the top five.

Rossi feels that Yamaha's new updates are clearly better but admitted that it was a "surprise" to see all four M1s high in the order, which proves that the bike suits the Misano circuit.

"The two days of testing after Silverstone [at Misano] was positive for us because we work very hard especially on the new stuff and at the end for me was quite clear that the new stuff is better," said Rossi.

"We decided to concentrate on this. It's a good start, a good Friday. Looks like that all the Yamaha [riders] are very competitive and is a bit of a surprise.

"It is a good feeling because looks like that also with the different configuration between me, Maverick and also with the Petronas team, our bike work very well here in Misano.

"We have good grip and in acceleration we are not so bad, in the time attack we are good and also the pace is good.

"Is also true that also Quartararo and Franco have the normal stuff and they are fast. Is also the marriage between the bike and the track."

Rossi added however that he is not yet completely happy with the bike, saying: "For me personally, we have a lot to do still because I don't feel fantastic with the balance of my bike.

"They need a bit more grip in acceleration. In time attack I am in P4 but I need to try to be closer to Vinales and Quartararo."

Vinales didn't use the new swingarm and exhaust as he is not yet convinced that it is an improvement, but is ready to switch to them if Rossi shows big steps forward.

"We need to do more laps to understand better, what it brings to the bike or not," said the Spaniard. "But anyway somehow I get a good feeling with the standard bike and I don't want to change that feeling.

"For sure if it's necessary I will try. If we see that Valentino is fast, constant, have a very good rhythm, we will try - but at the moment I have better feeling with the standard bike."

Quartararo meanwhile said that he was "not 100 percent confident", which makes his second place in the Friday timesheets behind Vinales all the better.

"The conditions were pretty strange today, we didn’t have a lot of grip. I had memories of two weeks ago on braking when we could brake like animals in the first corner, in the hard braking," he told BT Sport.

"Today I was not so confident, so today it was really good that we are P2 when we are not 100 percent confident with the bike."

Additional reporting by Matteo Nugnes