Rossi: I need to start winning

The reigning champion finished second at both Losail and Motegi - having been unable to catch the dominant Casey Stoner in Qatar and then lost the lead to team-mate Jorge Lorenzo halfway through the Japanese Grand Prix.

Those defeats have frustrated Rossi, who does not think he can retain his title purely through consistency and is determined to resume winning.

"We've made a good start to the season with two podiums which shows we are consistent, but now we need to make the step up," he said.

"Motegi was a good race but we had one or two problems, which we need to fix."

He is optimistic that Jerez can be the scene of his breakthrough, especially as he has won five of the last eight MotoGP races held at the track.

"We have a lot of data from Jerez because we tested there twice in the winter so I hope that this will help us to find a good setting straight away," said Rossi.

"As a rule we are very strong at the track and it is always great fun riding there."

His team-mate Lorenzo heads to his home race full of confidence and leading the championship following his Motegi victory.

"My motivation is high because I am arriving as the world championship leader in my own home. I can't ask for more," said Lorenzo.

"I had a very good feeling in Japan, and I enjoyed riding the bike in every corner. I have to be careful however because I am still learning all the time how to ride with the new Bridgestone tyres."