Nadal Djokovic´s biggest threat in Melbourne

Rafael Nadal shapes as being the biggest threat to Novak Djokovic's chances of claiming a fourth straight Australian Open title. The Spanish world number one missed the opening grand slam of the year in 2013 due to injury as Djokovic completed a hat-trick of wins. Nadal returned from injury in style to complete a wonderful season with a 75-7 win-loss record, winning the French and US Opens. The Spaniard climbed to the top of the rankings and, along with Djokovic, more than doubles the points tally of world number three David Ferrer. But his world ranking has barely helped in the draw – particularly compared to his Serbian rival. Nadal faces Australian Bernard Tomic in a tricky first-round encounter, with entertaining Frenchman Gael Monfils, big-serving Canadian Milos Raonic, Japanese talent Kei Nishikori, Bulgarian up-and-comer Grigor Dimitrov and Argentine star Juan Martin del Potro in his quarter. Brit Andy Murray – runner-up at Melbourne Park in three of the past four years – joins 2008 finalist Jo-Wilfried Tsonga and Swiss maestro Roger Federer in Nadal's half. That leaves the far less threatening quartet of Ferrer, Stanislas Wawrinka, Tomas Berdych and Richard Gasquet in Djokovic's half. Wawrinka last beat Djokovic in 2006 – but pushed the six-time grand slam champion to five sets in Australia and the US last year. Ferrer has lost eight straight to Djokovic, Berdych is 2-15 against the 26-year-old and Gasquet's last and only victory over the Serb was on carpet in 2007. The arrival of several former greats as coaches may have some impact. Ivan Lendl remains Murray's coach, while former world number ones Boris Becker and Stefan Edberg have joined the Djokovic and Federer camps respectively. Former French Open champion Sergi Bruguera joins Gasquet, Nishikori has hired Michael Chang, while once Wimbledon winner Goran Ivanisevic has teamed up with Croatian countryman Marin Cilic. Brisbane International champion Lleyton Hewitt looks to be turning back the clock after wins over Federer and Murray in the lead-up to his home grand slam. Djokovic's favourable draw could be a huge advantage come the second week, especially with hot temperatures expected in Melbourne. No day will be cooler than 38 degrees during the first five days. And that could be crucial come the business end as Djokovic looks to become just the second man to win four straight Australian Opens, joining six-time champion Roy Emerson (1963-67).