Valentino Rossi, YamahaValentino Rossi believes he will be hard-pressed to beat Yamaha teammate Jorge Lorenzo and Honda duo Dani Pedrosa and Marc Marquez on the basis of MotoGP testing so far.

Seven-time champion Rossi was fourth quickest on the final day of this week's test in Malaysia. Although he has been close to the front-running pace throughout the winter, Rossi now feels he will have to dig very deep to beat last year's title combatants Lorenzo and Pedrosa, and rising star Marquez.

"The Hondas are both very fast and Lorenzo is impressive," Rossi told the official MotoGP website. "For me to fight with those three guys we need to give the maximum effort and maybe more."

Rossi admitted that the Sepang testing week had not run smoothly.

"The balance is not so bad but we struggled a bit more compared to the first three days," he said. "We were a bit unlucky because we had a lot of small problems with the bike, especially yesterday and today. It made the work go slower for us. But at the end I was able to improve my lap time and stay in fourth place, not so far from Jorge."