Passion returns for healthy Nadal at Australian Open

Rafael Nadal insisted on Sunday he was healthy, motivated and ready to roll up his sleeves for this week's Australian Open as he sets about challenging Novak Djokovic as the top player in men's tennis.

The Spanish world number two lost to Djokovic six times in finals in the Serb's sensational 2011 season and admitted he had "a little bit less passion for the game" during the ATP World Tour Finals in London last November.

But Nadal said he was over the shoulder trouble that plagued him late last year and was ready to start with a fresh slate this year, although he plans to take February off for extra recuperation.

"I'm in Australia with a big motivation, with big passion, I'm happy, I am practising well. I'm enjoying everything. I will try to be ready for tomorrow," he said.

Nadal, who opens his campaign against American Alex Kuznetsov on Monday, has a chequered record at the Australian Open, winning in 2009 but failing to make the semi-finals in three of the last five visits.

The 10-time grand slam champion has no qualms about applauding Djokovic's amazing last season when the Serb won three of the four majors and put together a 70-6 winning record.

"Novak is the best because last year he had a fantastic year," he said.

"He's the number one. He deserves to be there and I will be fighting for every moment to try to compete against everybody."

"It's just the beginning of the season and I will try to improve a few things that probably I will need."

"I am healthy. That's the important thing. I am ready to work hard."

Left-hander Nadal is adjusting his game to a new heavier racquet aiming to develop more power into his already physical back-court game.

"It gives me a little bit more power. It's three more grams and for a few balls, for the higher balls, you can hit the ball a little bit more flat because the racquet goes faster into the ball," he said.

"The racquet goes quicker. You lose a little bit of control in the beginning but after a few months you feel like it is your racquet."

"I did it because I believe it can be a really positive thing to help me in a few aspects of my game."

"It's working well in practice. In Doha I had really positive feelings."