World number four Andy Murray admits he still needs to improve his serve if he is to break his grand slam duck at the Australian Open later this month.
The Scot, who was beaten in the final at Melbourne Park by Roger Federer last year, begins his 2011 season on Monday at the Hopman Cup, where he and Laura Robson will represent Britain in the mixed team event for the second successive year.
Looking fit and strong after a month of training in Miami, Murray said the form of world number one Rafa Nadal and 16-times grand slam champion Federer meant it would be even tougher to win one of the sport's four biggest events.
"Last year's Australian Open was one of the best events I've played in my life," Murray said at a press conference on Sunday. "I played some of my best tennis so I'll have to play even better if I want to win because Rafa and Roger are playing so well just now."
Murray, whose other grand slam final appearance came at the US Open in 2008, said he had been focusing on particular areas of his game in the short off-season.