Yamaha's Valentino Rossi says he is “in trouble with the tyres” over a race distance after a tricky day of practice at Jerez ahead of the MotoGP Spanish Grand Prix.
Rossi was sixth in the opening session of the day, but slumped to ninth in the afternoon as the temperatures rose.
Jerez proved to be one of Yamaha's worst circuits last year, the heat and poor track surface causing problems with grip and tyre life.
The track has been resurfaced since, but Rossi is still battling with grip issues on his Yamaha, while also finding the bike balance to be weak as well.
“It was a difficult day, especially in the afternoon, because in the morning I wasn't so bad, with the lower temperatures, but unfortunately with the higher temperatures we suffered,” said Rossi.
“I'm not happy with the balance of the bike, we need to improve. But we are also in trouble with the tyres.
“After some laps we lose grip and it looks like we have to slow down more than our opponents, so I think that will be difficult.
“But it's only Friday, we need to work and improve, and we will try to better our understanding tomorrow.”
Team-mate Maverick Vinales also suffered from similar problems, the Spaniard complaining of a lack of traction on his Yamaha.
“Honestly, today I didn't have the best feeling,” Vinales, who was 12th overall on Friday, added.
“I wasn't feeling well during FP1 and FP2, it was difficult. In Austin we improved quite a lot, bt since coming here the problems started again.
“The bike is moving around a lot, so we have to keep working and stay focused and we have to push – that's the only way forward.
“Vale seems to be having the same problems, our laptimes are quite similar. We have to find a solution that works for us.”