Valentino Rossi was helpless to prevent Andrea Iannone and a place on the Austin MotoGP podium inch away from him during Sunday's race at COTA.

The Movistar Yamaha rider realised Marc Marquez and Maverick Vinales were a step ahead, but thought he had the pace to challenge the Suzuki rider.

However the hotter race day temperatures saw Rossi on the limit in the fast corners and he remained in fourth position from lap 2 to the chequered flag, crossing the line almost three-seconds from Iannone and four in front of championship leader Andrea Dovizioso.

"It was a good weekend, because I was always in the top five," Rossi began. "But in the race, I hoped and I expected to be a bit stronger to try to fight for the podium.

"I know that Márquez and Maverick were a bit stronger. But I hope that I was fast enough to fight for the podium with Iannone, but Andrea was faster than me and I was not able to arrive to attack.

"I hoped to have 2m 5.5, 2m 6 pace because Friday afternoon and also Saturday afternoon I was on that pace. And I know that with that pace I can fight for the podium, the target was to fight for the podium.

"But unfortunately I suffered more with the heat, especially with the front tyre.

"I never suffered during the practice, but today, especially in the fast corners, I was too much on the limit. So I had to slow down a little bit, try to stay close to Iannone for the podium, but he was stronger than me.

"At the end unfortunately, I wasn't able to fight."

Like the majority of the field, including the three riders on the rostrum, Rossi chose to race the medium compound front tyre.

"We need maybe to make a different balance of the bike maybe, because for us, the hard front doesn't work," he said, before ruling out the bumpy track as the problem.

"The bumps are there for everybody, and they were also there on Friday and Saturday, but on Friday and Saturday, I felt better. For me it was more the temperature."

Although 'not completely happy' Rossi was pleased to see two (edit) Yamahas in the top four - and three in the top six, counting Tech3's Johann Zarco - at a circuit where they have never won.

"It means that we are quite competitive," he said.

"Now it will be very important to understand our speed in Europe, because in Europe everything will change. Last year we suffered a lot, so already from Jerez, we can understand if we are faster.

"I think and I hope that we can be more competitive, but we have to wait for next week."

Rossi is seventh in the world championship, 17 points behind Dovizioso, after the non-score in Argentina.