While new team-mate Maverick Vinales one again ruled the timesheets, Valentino Rossi left the Phillip Island MotoGP test 'not very happy'.

The nine-time world champion didn't do a long run, or push on new tyres, making his pace harder to pinpoint.

But the Italian was clearly downbeat after sliding from second (+0.186s) on day one, to eleventh (+0.921s) at the conclusion of day three.

"I suffer quite a lot with both tyres, especially the front. For sure this temperature and these conditions are completely different to the Grand Prix. It was a bit too soft. But sincerely it was not my main problem.

"Today we worked a lot on the pace for the second half of the race, because we suffered in that area last year. We tried something quite different, but in the end we didn't improve a lot, so we'll have to try something else," said Rossi.

"I think the bike has good aspects, especially the engine, but for sure this test was more difficult for me than the one in Sepang. I'm not very happy and we need to try to do better."

Rossi, who celebrated his 38th birthday on day two, has finished MotoGP title runner-up for the past three seasons.

While the Italian did not push for a late lap time on Friday, he appears to be content with the M1's ability over a single lap. Ensuring he can maintain that pace, especially in the face of Marc Marquez's incredible consistency, remains the priority.

"We have something else to try. For me the potential with the new tyres is not so bad. We have to improve after some laps."

Rossi also confirmed his preference for Yamaha's newest chassis, that he back-to-back tested with another frame from the end of '16. "Yeah, for me the second spec, the new one is better," he said.

Team boss Massimo Meregalli did confirm to Crash.net however, that Yamaha will continue to run back-to-back tests at the next preseason test.

Just one more test, at Qatar, remains before the new racing season begins.