NOVAK DJOKOVIC has vowed to take a "humble" approach to his bid for a fourth Australian Open title in the space of five years, despite being the odds-on favourite.

Djokovic's 25-match unbeaten run in Melbourne came to an end when he lost to eventual champion Stan Wawrinka in the quarter-finals last year, but the 27-year-old went on to win seven tournaments in 2014, including Wimbledon and the ATP World Tour Finals.

That meant the Serbian begins 2015 as world number one and top seed, but Djokovic is taking nothing for granted ahead of a first-round clash with Slovenia's Aljaz Bedene on Tuesday.

"I don't think it's nice to talk about the title already when the tournament hasn't started yet," Djokovic said. "There are so many players who are contenders to win the title.

"Considering the success that I had in my career in this tournament (it) gives me enough reason and confidence to believe I can go far. But I have to start the tournament well. It's the beginning of the season.

"We already have one of the four biggest tournaments in our sport. 128 players want to prove that they deserve to be in this tournament and they have, of course, huge motivation to win against the top players.

"It's something that is obviously keeping us all cautious, and we have to have a right and humble approach to the tournament. So I'll take it one match at a time."

Djokovic's first match could almost have been an all-British contest, with the Lawn Tennis Association keen to get the seven-time grand slam champion to switch allegiance in 2006.

Bedene, who has lived in Britain since 2008, has also applied to become a British citizen and wants to play for his adopted nation in the Davis Cup.

Djokovic said. "If he thinks it's the proper way for him to continue his tennis career, then I support him in this intention.

"Obviously at that stage of my life things weren't easy, trying to find proper conditions and proper support for my career. At that time the country (Serbia) was going through a lot of troubles, economical troubles. They had better things to do than support financially a 15-year-old tennis player.

"In my case, in the end there was no doubt that I want to stay playing for my country because that was just a few years of struggle."

Djokovic was forced to postpone his pre-tournament press conference by a day due to illness, but practised on Sunday and declared himself fit to seek a fifth win in the year's first grand slam.

"I had a tough couple of days but it's all behind me now. I'm ready for the Open," he said. Asked what he had been suffering from, Djokovic added: "Little bit with the flu and stomach. But I carried that already from the Middle East a little bit. But now it's good. It's passed."

Djokovic was unable to play Britain's Andy Murray in the final of an exhibition event in Abu Dhabi at the start of January due to illness, and then reached the quarter-finals in Doha before losing to Ivo Karlovic.

Defending champion Wawrinka is seeded to meet Djokovic in the semi-finals and comes into the event in confident mood after defending his Chennai Open title last week, defeating Bedene in the final.

"I feel great coming here," Wawrinka said. "I've been getting a lot of confidence, winning the first tournament of the year. I feel ready to start.

"It's been a crazy 2014 year for me, winning a grand slam, a Masters 1,000 event (Monte Carlo), finishing with the Davis Cup trophy. That's something amazing as a tennis player, something that you can only dream about it.

"But now it's a new year. Everybody starts at zero again. You have to be ready to play great all the year."

ends