Nadal returned to win two Grand Slams after career-threatening knee injury
Andy Murray is the third favourite for the title. The Briton won the 2013 Wimbledon to become the first male British winner in 77 years. He also reached the final in Melbourne three times but failed each time, including last year when he lost to Djokovic in four sets.
But the fourth seed is not match fit as he took a back surgery in September. He returned in Qatar but lost to German Florian Mayer in Round 2, which means he will go into this year's first Major having just played two exhibitions and two ATP Tour singles matches.
Last year was a bad one for Federer as the Swiss legend won just one title and failed to reach the final of any slam, which was the first time for him since 2002. He also dropped out of the top-5 and suffered a shock defeat to Lleyton Hewitt in the final in Brisbane last week.
IANS
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