Marquez wary of Vinales threat in Austin

Honda rider Marquez has never lost at Austin since the track was added to the calendar in 2013, but ended up second-fastest on the opening day of action of COTA behind Suzuki's Andrea Iannone.

Vinales - who is in the midst of an 11-month win drought - was third, just two tenths slower than Marquez, and the reigning champion said the difference in race pace between himself and his Yamaha rival is small.

“I have a good pace, but Vinales is close,” said Marquez. “It’s true that I’m a step ahead, but there’s not much difference either.

“I did my best laptime with the hard rear and I was with the soft front because when I crashed with the medium there was a little bit damage and we changed [bikes].

“Anyway still in the setup of the bike we can improve a little bit. I'm fast, but I didn’t find the correct feeling so we need to improve.

"About the race I feel good. Of course we have a good rhythm, at the moment the best one, but the most important will be on Sunday and at the moment Vinales is not far.”

Vinales trying to rely less on electronics

Vinales had said he would request a more "wild" Yamaha - with less electronic interference - after the previous round in Argentina, and revealed on Friday that the changes made to the M1 were working well.

"Honestly in FP2 I felt great," said Vinales. "I felt I could still ride much faster than what I did. I think lap by lap, it’s gonna improve.

"From Argentina we improved a lot the exit of the corners, we have to keep working on that.

"Last year I had much more aggressive electronics, and you know, controlling more by the hand than the traction control, it’s what I’m looking for right now. And I think it seems to work.

"Tomorrow I try a little bit more this side, let’s see also if it’s wet if it works. I’m quite happy overall and we’re gonna try to push tomorrow."

Additional reporting by Oriol Puigdemont