Marlboro Ducati's Valentino Rossi is still worried about the gap in performance to the Honda and Ducati MotoGP teams even though a change in weight distribution saw him ride to a hard-fought sixth place at Mugello today.

Rossi's team, which is operating without Jerry Burgess this weekend, increased the GP11.1's ride height by 20mm in morning warm-up today which gave The Doctor more feel at on the front tyre, but he is still desperate for more.

"Today is a little bit better as this morning we did a great modification to the setting of the bike and it has become better so I was able to make a better rhythm and we were more close. We have to work on this setting because we improved the turning but we lose a bit of grip but we can work on this for the new bike," said Rossi.

"The problem remains with braking and entering and there's not enough feeling from the front. I lose a lot in the fast part where I have to ride the bike from one side to the other. We have to work on the soft and the hard tyre for to try and fix the problem on the front as soon as possible.

"We changed a little bit the weight distribution on the bike for better turning and grip and this work but I slide a bit too much on the rear, especially from the last corner, so we need to keep the good things about the turning but without lose too much grip.

"We are worried because we need to take a big step to win and to fight with the Yamaha and the Honda."