Ducati's Valentino Rossi was less than half a second off the pace of Dani Pedrosa and Jorge Lorenzo at Brno today, giving the Italian superstar cause for 'optimism' this weekend.

Rossi, who will switch to Yamaha alongside Jorge Lorenzo in 2013 after an unsuccessful association with Ducati, was sixth fastest for the Czech round of the MotoGP world championship on the first day of practice.

The nine-times world champion, who is Ducati's sole factory rider this weekend after Nicky Hayden was ruled out of the race through injury, said his pace on the Desmosedici was 'decent'.

"I'm happy because we went pretty well today, and in particular, the gap to the front makes us fairly optimistic," he said.

"This is a beautiful track that I like a lot. It's where I got my first win and my first world title, and we were also pretty strong here last year on the Ducati.

"Both of today's sessions were good. We worked well, trying to find the best set-up compromise for this circuit, and when we put on the soft tyre, we were finally able to improve the performance and to do a number of laps not too far from the leaders' times. The pace is also decent."

Rossi acknowledges that he will have to improve further tomorrow to have any chance of challenging for a top three finish.

"The riders ahead certainly still have some margin, so tomorrow, in addition to choosing which tyre to use in the race, we'll have to try to improve a bit ourselves as well. At the moment, the soft is performing better, but we'll see," he said.

Meanwhile, Hayden - who injured his hand at Indianapolis - has reported that he is confident he will return to action at the Misano Grand Prix.