World number one Novak Djokovic has said that he hopes to improve his game during the upcoming season.
In a remarkable 2011, the Serbian won three Grand Slam titles and lost only six matches.
"There's still room for improvement," he said. "That's something that I am aiming for.
"The game that I have is good enough to be one of the best on all surfaces so I just need to maintain that level and always improve certain strokes in my game by certain percentage.
"I need to believe I can repeat this year again. Of course, it's going to be an incredible and a difficult task to achieve, but you never know. Nothing is really impossible."
Djokovic will be competing in Dubai's Mubadala World Tennis Championship exhibition event, which begins on Thursday, December 29.