Valentino Rossi: Wins, championship top three achievable in 2013

The seven-time champion suffered the first two winless seasons of his career at Ducati, leading to him deciding to rejoin Yamaha in August last year.

While he admits it will be difficult to match team-mate and reigning champion Jorge Lorenzo and Honda's Dani Pedrosa, Rossi said failing to win at least once in 2013 would be a major disappointment.

"I'd like to have plenty of podium finishes, at least 10, and to finish in the top three in the championship," Rossi told Gazzetta dello Sport.

"If I didn't win but was on the podium every Sunday it might be OK. But a victory would be the watershed.

Asked if he would rue not winning, Rossi added: "Yes. The objective is to win, which I've not done since 2010."

Rossi warned that he would need time to settle before he can think of beating Lorenzo, but he does believe a podium in the season-opener at Qatar is possible given Yamaha's pace and the fact Honda's Marc Marquez will be contesting his first MotoGP race.

"Even if I'm not competitive with Lorenzo and Pedrosa, I need to try to be not far behind them. And it's still to be seen how Marquez will do.

"It will take time to beat Lorenzo: he'll be quicker at the start.

"His strong point is that he knows the Yamaha well and is better at riding it; I'll have to settle in bit by bit.

"The M1 is competitive though. When I tried the bike at the end of last season I found it to be good. Its acceleration has improved a lot."

Rossi, 33, added that despite reaching a 'certain age' he starts the season in the best physical and mental shape he has enjoyed for years.

"I'm more motivated than I would have been if I'd stayed at Yamaha [in 2011-12] - maybe I've become younger," he explained.

"[I feel] good, better than the last few years - above all 2010 when I had the operation on my shoulder which was no laughing matter. Now I am ready and in form.

"I know it will be difficult to come back after two disappointing years but I am very motivated. I'll do better with Yamaha."