Djokovic sees Roger-Rafa dominance waning

World no.3 Novak Djokovic believes Roger Federer and Rafa Nadal's stranglehold on men's tennis is slowly loosening.

The Serb said the rise in genuine contenders capable of breaking the grand slam dominance of Federer and Nadal gave a boost to the sport.

"I think it's getting very interesting, men's tennis," Djokovic told reporters at Melbourne Park.

"It's good for the sport to have a good group of players able to win a major event or a grand slam," added Djokovic, one of only two players other than Federer and Nadal to win a grand slam title in the past 19 majors when he won the 2008 Australian Open.

"The last five, six years the dominance was obvious from Federer, Nadal. They've been winning all the grand slams they've played. But now in the last two years or so things are changing a little bit... we have more belief that we can win a grand slam."

Djokovic, Andy Murray, Juan Martin del Potro, who won the US Open last year, American Andy Roddick and Nikolay Davydenko all present threats to the Swiss no.1 and Spanish no.2.

The Serb played at the invitational Kooyong Classic as his only warm-up ahead of his Australian Open first round match and has deliberately adopted a more low-key approach to remain fresh.