World ranking: 1
Career singles titles: 28
Grand Slam singles titles: 4 (Australian Open 2008, 2011, Wimbledon 2011, US Open 2011)
Career prize money: 32,882,760 dollars
Best Australian Open result: Champion (2008, 2011)
Coming off a stellar 2011 with 10 titles in 11 finals after beginning the year with a 43-match unbeaten run. Djoker won three of the four Grand Slams last year and was the first player other than Roger Federer or Rafael Nadal to finish a season as number one since 2003, the year he turned a professional player. His playing style is favoured by hardcourt surface at the Australian Open.
World ranking: 2
Career singles titles: 46
Grand Slam singles titles: 10 (Australian Open 2009; French Open 2005, 2006, 2007, 2008, 2010, 2011; Wimbledon 2008, 2010; US Open 2010)
Career prize money: 45,114,407 dollars
Best Australian Open result: Champion (2009)
Nadal Finished in top-two rankings for the seventh straight year. He clinched a sixth French Open last year to equal Bjorn Borg's record, but was runner-up to Novak Djokovic at Wimbledon and US Open. The Australian Open is his least successful Grand Slam with just one win, one semi-final and three quarter-final appearances in his last five visits to Melbourne.
World ranking: 3
Career singles titles: 70
Grand Slam singles titles: 16 (Australian Open 2004, 2006, 2007, 2010; French Open 2009; Wimbledon 2003, 2004, 2005, 2006, 2007, 2009; US Open 2004, 2005, 2006, 2007, 2008)
Career prize money: 67,479,965 dollars
Best Australian Open result: Champion (2004, 2006, 2007, 2010)
Roger Federer had no Grand Slam title last season for the first time in nine years and was runner-up to Rafael Nadal at the French Open after his stunning win over Novak Djokovic in the semi-finals. He is the winner of four Australian Opens. Age may be catching up with the all-time Grand Slam champion but he is always difficult to beat in the best-of-five-sets format.
World ranking: 4
Career singles titles: 22
Grand Slam singles titles: 0
Career prize money: 19,221,761 dollars
Best Australian Open result: Runner-up (2010, 2011)
Andy Murray has constantly been under pressure to end his country's 76-year wait for a Grand Slam men's singles champion. He has been the runner-up at the last two Australian Opens behind Roger Federer and Novak Djokovic. He started the new season with victory in the lead-up Brisbane International and is now coached by tennis great Ivan Lendl.
World ranking: 6
Career singles titles: 7
Grand Slam singles titles: 0
Career prize money: 8,478,346 dollars
Best Australian Open result: Runner-up (2008)
Tsonga is the top-ranked French player who finished in the top 10 for the third time in four years. His best run at the Australian Open was four years ago when he beat Andy Murray, Richard Gasquet and Rafael Nadal before losing to Novak Djokovic in the final. With a powerful all-court game, Tsonga looms as the best chance outside the top four.