Updated

MELBOURNE (Reuters) - A year ago, a relaxed Rafa Nadal walked into the main news conference room at Melbourne Park and faced the assembled media.

"Hello guys," the then 22-year-old said with a beaming smile. "Welcome back. Did you have a good break?"

The mantle of the world's best player had been passed from the Swiss maestro to the muscular Mallorcan, who appeared to have laid the foundations for a lengthy dominance of the men's game.

Less than five months later, that air of invincibility disappeared and the regime was dismantled.

Then Nadal's aching knees, screaming after years of the rapid stop-start nature of the game and sliding on clay courts in his homeland, finally told him "enough" and forced him out for more than two months.

He missed the defense of his Wimbledon crown, which Federer regained a year after the pair had fought out a tense five-set battle that many described as the one of the greatest grand slam finals of all time.

When he returned for the North American hard court season he struggled to rediscover his form, though he still advanced to the quarter-finals in Montreal and semi-finals at Cincinnati, suggesting he could peak for the U.S. Open.

Juan Martin del Potro, however, had other ideas with the Argentine dismantling Nadal 6-2 6-2 6-2 in the semi-finals at Flushing Meadows.

He admitted at the time he needed to recharge his batteries and find confidence from somewhere.

DAVIS CUP VICTORY

That confidence may have received a boost when he was back to his fist-pumping, yawping best when he helped Spain to Davis Cup victory over the Czech Republic in Barcelona in early December.

After a short break he, then made the final of the Qatar Open in Doha earlier this month, losing to Russia's Nikolay Davydenko.

The defeat, however, ominously continued a poor run against top-10 players since his return from his enforced break.

He has beaten just one other top-10 ranked player in that time and pundits are now questioning whether he can recover his confidence and form in time for his Australian Open defense.

"I am not saying I am going to win the tournament, you never know before a tournament," he was quoted as saying Britain's Guardian newspaper during the Qatar tournament.

"I have played well enough to have a positive result (at the Australian Open), but I don't know.

"You have to see the conditions. I am ready to win the tournament, but I am never going to say that I am going to win it.

"The only thing I can say is that I am playing well enough to have a positive result.

"And I am happy."

An early indicator of how true that may be could be whether the cheery greeting and smile returns for the media at Melbourne Park again this year.

(Reporting by Greg Stutchbury in Auckland; Editing by John O'Brien)