The world number three is coming off an impressive second half of 2010 in which he reached the US 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.

"All these guys have improved so much and then you have (Roger) Federer and (Rafael) Nadal, who keep on playing better and better." Since the start of 2005, only three players, Marat Safin and Djokovic in Melbourne and Juan Martin Del Potro at the US Open, have broken Nadal and Federer's stranglehold of the Grand Slam events.
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."