Movistar Yamaha's Valentino Rossi was bursting with enthusiasm after returning to action on day one of the first Sepang MotoGP test following the winter break.

The nine-time world champion posted the second fastest time on his factory YZR-M1 in 2m 0.380s to finish only 0.118s adrift of Repsol Honda's Marc Marquez.

Rossi, who finished last year's championship as the runner-up behind Marquez and top Yamaha rider, has yet to test Yamaha's seamless downshift gearbox, but the 35-year-old hopes the technology - already being utilised by Marquez and Dani Pedrosa - will be available 'as soon as possible'.

Related Articles

"This is the way Yamaha works, small steps, but it is always 99 per cent better. You make a small step but you are sure that if Yamaha brings something, then it is something better," Rossi said.

"This is good also for the rider because you can understand in a better way the bike. I'm happy because it seems like the difference between us and the factory Honda remains the same as at the end of last year.

"I don't know about the gearbox, I hope it will arrive as soon as possible but anyway we have a lot to do. For sure I want to try and I hope as soon as possible, but you cannot joke with the gearbox and I am happy to try the gearbox when it is 100 per cent sure."

The Italian star joked that he was concerned he may have forgotten how to ride a MotoGP bike fast, but it was clear on the opening day at Sepang that Rossi has picked up where he left off last season.

"It was a positive first day back on the bike and I am satisfied because I was strong. It's always a big emotion to come back on the bike because always you have the feeling that maybe you forget the way to ride!" he said.

"But I'm still able to ride and it was good because I was competitive from the beginning to the end. I did a good lap time with the new tyre, but also with the older tyre my pace is very similar to [Marc] Marquez and [Jorge] Lorenzo and also [Dani] Pedrosa, which is good.

"I'm happy especially because the bike is good; first impressions are so positive because you can push when you ride and it looks like the bike is also a little bit faster," added Rossi.

"We have a lot of small details to work with and also we have some for tomorrow, for the second day and it is interesting work. It is always a pleasure to come back and understand that we are competitive; at the end Marquez beat me but it was just one tenth, so I'm not so bad."

Rossi is concentrating much of his focus on maintaining a fast pace on used rubber in the closing stages of a race scenario, all too aware that chief rival Marquez's ability to churn out fast laps at the end of a race is one of the defending world champion's strongest attributes.

"We are there, we are close and we work very hard to keep pace with the used tyre in the last five laps of the race because at the end of last year we were losing [time] compared to Marquez," he said.

"I work a lot on my riding still and I think this is the way to try to remain competitive. Last year I did a big step but I have a margin to improve and I try to improve the braking, the entry; I try to work at the ranch and also this week I work with different types of bikes.

"Fitness is important and I'm not at 100 per cent now; I work, I'm ready, but I try to arrive at 100 per cent for Qatar," added Rossi.

"For me it's very important [dirt track riding] for controlling the front; it's good training and also for fitness and also it looks like it's not very dangerous, like motocross or something else. And also it's very fun!"