Ducati's Valentino Rossi has described his pace during the opening day of practice at Assen for Saturday's Dutch TT as a 'decent step forward'.

Rossi ended the day just ninth fastest on combined times, but the Italian superstar was only four tenths of a second behind Ben Spies at the top of the times.

The nine-times world champion managed his best time on the harder compound rear tyre - albeit whilst following Dani Pedrosa - putting him as high as fourth, before he ended the afternoon with the eighth quickest time.

Rossi, whose team-mate Nicky Hayden set the third fastest time on a soft compound rear in the afternoon heat, said:

"Today went pretty well, especially in the afternoon. I'm eighth, but the gap to the front is only four tenths, which is a decent step forward for us.

"Now the bike works well with new tyres, but we have to keep working on our race pace," he added.

"Both Nicky and I start sliding a lot when the tyre is worn, so we have to slow down too much compared to the others.

"Tomorrow, in order to be more consistent and improve the pace, we must try to improve rear grip without losing it at the front. Anyway, today wasn't a bad start."