Spain's Rafael Nadal has been top seeded at the Australian Open, above Swiss great Roger Federer at two, followed by Bulgaria's Grigor Dimitrov, Germany's Alexander Zverev and Dominic Thiem of Austria.Serbia's Djokovic, who is making a comeback after a six month lay-off due to a tennis elbow injury, is ranked at 14. He is chasing a seventh Australian Open title and started off well with a reassuring 6-1, 6-4 win at the Kooyong Classic on January 10. "I don't want to be over confident but I'm very, very happy with how it went today," Djokovic said after the match.At the 14th rank, Djokovic may run into a tough opponent early on but the win against Thiem has set him up as a potential finalist. Despite the tournament suffering due to withdrawals by Andy Murray and Kei Nishikori, the return to fitness of Djokovic and hopefully Nadal too opens up the tournament.In women's rankings, Romanian Simona Halep tops the chart followed by Danish player Caroline Wozniacki, Spanish-Venezuelan Garbine Muguruza, Ukraine's Elina Svitolina and America's Venus Williams. Muguruza is injured and is not sure if she will take the field.The US Open winner Sloane Stephens, who has been struggling with her form, has been seeded 13th.