Valentino Rossi says Yamaha will need to improve his bike's traction before tomorrow's Portuguese Grand Prix if he is to beat team-mate Jorge Lorenzo.
While Lorenzo took a comfortable pole at Estoril, Rossi had to dig deep to beat Casey Stoner to second on the grid.
"We are working hard," Rossi told Italia1. "At Misano we immediately found a good set-up, while here we are still working on it. We are not 100 per cent, but we aren't far off either. Especially with the soft tyre I went quick and did some good lap times.
"To start second tomorrow is very important. We must improve more, we lack some traction at the exit of slow turns. I lose a bit of time here and there around the track, so we'll try to do a bit better tomorrow. I struggle a bit in T3."
Last year Estoril was one of the few tracks where Michelin had an advantage over Bridgestone, and Rossi suspects that now that everyone is on the Japanese rubber, the whole field could suffer from wear issues in the closing stages of tomorrow's race.
"We'll have to see what the race pace is tomorrow, also because this is a difficult track for the Bridgestones, as we saw last year," he said.
"This year we are all in the same boat, but I think the last ten laps will be very difficult, so to have a well-balanced bike that you can control when the tyres slide will be fundamental."