By Simon Cambers
The world number three is coming off an impressive second half of 2010 in which he reached the U.S. Open final and then inspired Serbia to win the Davis Cup for the first time in their history.
The Serb said he had improved a lot in the three years since he won his first and only grand slam but unfortunately, so had the rest of the world's top players.
"I am (better) but now there are a lot more good players who I think have improved their games tremendously," he told reporters. "I think (Robin) Soderling is playing great, (Andy) Murray, (Nikolay) Davydenko.
Djokovic may be breathing down their necks but knows that there is still a long way to go to if he is to taste grand slam glory again.
"They're the two best players in the world, deservedly," he said. "I guess I'm in this small group of players behind them that is trying to challenge them in each event.
"How far back? I can't say. Rankings are showing everything and the results they have made make them probably two out of the five best players to ever play this game."
Djokovic also dismissed fears that his 2010 season, which extended into December because of the Davis Cup final, would affect his chances of glory.
"I had a very short off-season but I am feeling well," he said. "I had some problems in the past (with the heat) in Australia so I really wanted to physically be fit for the tournament.
"But tennis wise, I played a lot in the last two, three months and as soon as I started again I already felt that I'm hitting the ball well. I tried to work just on some specifics and I'm happy with the way that work has been done."
Like all the players, Djokovic's preparations over the past few days have been affected by the inclement weather.
But having pulled out of his quarter-final in Melbourne in 2009 because of cramps and heat exhaustion, he said he had not been unduly bothered by the recent unseasonable weather.
"I'm probably one of the few players that loves rain in Melbourne," he said.
(Editing by John O'Brien)