Rafael Nadal poses biggest threat to Novak Djokovic's reign

After staging a remarkable comeback in 2013, Spanish buccaneer Rafa Nadal has his eye on more grand slam silverware this year and is shaping up as the biggest threat to Novak Djokovic's Australian Open reign.

While Nadal reasserted his hegemony over Roland Garros with an eighth French Open triumph last year and Roger Federer has won seven Wimbledon crowns, Djokovic has made Melbourne Park his own grand slam banker with four titles in the last five years.

The Serbian last tasted defeat on the banks of the Yarra River almost four years ago and if he can extend his unbeaten run on the blue plexicushion to 28 matches this year, would become the first man in the professional era to take the title five times.

"The Australian Open is definitely my most successful grand slam, my favourite grand slam. I love spending time here," Djokovic said after being drawn to face world number 90 Lukas Lacko in the opening round on Friday.

"It's the start of the season and I think most of the players are sharing the same opinion. We love the atmosphere, the easy energy that flows around, and of course the tennis fever."

Nadal missed the tournament in 2013 when a bout of stomach flu capped a miserable run of injuries but made a remarkable return with 10 titles, including his 12th and 13th in grand slams, to knock the Serb off the top of the world rankings.

So while Federer, also a four-times Australian Open champion, and Wimbledon champion Andy Murray, a finalist in three of the last four years, cannot be written off, Nadal looks the man most likely to usurp Djokovic.

Nadal opened the new season with another title win in Qatar and few tennis fans would be too disappointed if the two weeks of competition at Melbourne Park, which start on Monday, climax with a re-match of his six-hour 2012 final defeat to Djokovic.

The Spaniard certainly has the tougher draw with the talented but inconsistent Australian Bernard Tomic up first and Juan Martin del Potro, who beat him at the Shanghai Masters last October, his potential opponent in the last eight.

While Nadal has never been coached by anybody other than his uncle Toni, Djokovic has followed the trend of elite players adding former tennis greats to their support staff by taking on six-times grand slam champion Boris Becker.

"He is not happy with six grand slams, even though that is an incredible record in itself," Becker said on Friday.

"He wants to win more and he is having a good team around him that tries to make him better."

TOO SOON FOR MURRAY?

Briton Murray started the trend with his recruitment of Ivan Lendl and Federer recently followed suit by persuading Stefan Edberg to join him in Melbourne.

Federer, 32, is looking to the Swede for inspiration as he tries to arrest last year's decline that saw the Swiss fail to reach at least the quarter-finals at successive grand slams for the first time since 2003.

Murray, meanwhile, is on the comeback trail after four months on the sidelines in the wake of surgery on his lower back and the consensus is that he might struggle with five-set matches so early in his return.

Del Potro and Lleyton Hewitt are the only grand slam champions apart from the "Big Four" of Djokovic, Nadal, Federer and Murray still active but the Argentine has not produced his best form consistently since a wrist injury that nearly ended his career in 2010.

The tall Argentine, still only 25, is seeded fifth after showing signs that he might be on the verge of being a grand slam contender last year with four titles and runs to the finals of the Masters tournaments at Shanghai and Indian Wells.

Third seed David Ferrer has reached the semi-finals in two of the last three years but beat an injury-hampered Nadal to do so in 2011 and this year's draw looks tougher than the fairly easy ride he had in 2013.

Tomas Berdych, Stan Wawrinka and 2008 losing finalist Jo-Wilfried Tsonga are the other players who might provide an upset or make a run but few are looking beyond Djokovic and Nadal.

Although Nadal beat Djokovic in the U.S. Open final, the Serbian got engaged to long-term girlfriend Jelena Ristic straight afterwards and has been unbeaten since.

"Since I got engaged I haven't lost a match, so I guess the wedding should come soon. I should give credit for that," he said of a run which included thrashing Nadal to win the ATP year-ending championships in London.