Australian Open, Melbourne
Venue: Melbourne Park Dates: 17-30 January
Coverage: Watch on BBC TV, Red Button, BBC Sport website & Eurosport; listen on BBC 5 live sports extra and online; text commentary online;
Federer has been practising ahead of the year's first Grand Slam
Roger Federer's coach Paul Annacone has predicted that the world number two could extend his record Grand Slam tally to 20 titles.
"If he can stay healthy and happy and eager, I don't know what the end number would be. But is 20 realistic, sure, why not?" Annacone said.
Federer, 29, will bid for his 17th Grand Slam title at the 2011 Australian Open starting on Monday.
Annacone was hired by the Swiss after a quarter-final Wimbledon exit in 2010.
Federer has credited the Californian coach for his recent resurgence, capped by victory over world number one Rafael Nadal to win the season-ending World Tour Finals in November.
"He can win every tournament he plays. He's probably not going to, but he can win every match he plays and there's not a lot of guys you can say that about," Annacone, who works with Federer's Swiss coach Severin Luthi, told the Australian Open website.
Outlining his approach to coaching the world number two, Annacone, who has previously coached Pete Sampras and Tim Henman, added: "It's about combining the head, heart and talent components of a player, and understanding how they interact, the best way to match up against other players.
"And, ultimately, the best way for them to keep having fun doing it, and the best way to try to get better."
Federer kicked off his season with victory at the Qatar Open, when he thrashed Russian former top-10 player Nikolay Davydenko in the final.