GLASGOW, Scotland — Andy Murray believes he will be fit and ready to return to the ATP Tour by Dec. 31 at the Brisbane International.

He also thinks results will not come quickly, and aiming for the Australian Open title might be too ambitious. But he's sure he'll be challenging for major honours next year.

Murray hasn't played since the Wimbledon quarterfinals, where he limped out with a hip injury.

"When I get back on the court next year and start playing again, it might not come immediately at the beginning of the year," he said on Tuesday before a charity match against Roger Federer in Glasgow.

"I have been hitting the ball very well in practice - it's just that there is a difference between that 75-80 per cent practice and going flat out at 100 per cent for 2 1/2 or three hours on the match court. Until I do that I can't say for certain, but I'll be able to come back just fine."

The two-time Wimbledon champion plans on getting to Australia early to acclimatize in a bid to offset his lack of sharpness, but he will not feel compelled to play if he is not totally fit.

"Things have been going pretty well so far in the rehab, but you just never know," said Murray, whose medical team chose rest and recovery instead of surgery.

"I've been training for a few weeks now. Some days I've felt great and some days not so good. I probably made a bit of a mistake trying to get ready for the U.S. Open but it was the last major of the year and I wanted to give it a go. I'll come back when I'm ready."

Federer reinforced that message. He had a similar layoff last year after struggling with knee problems and came back rejuvenated, winning his first Grand Slam event for five years at Wimbledon and following it up with a U.S. Open triumph.

He told Murray: "Take your time, however long it takes. When you come back you want to be at 100 per cent, otherwise the problem is you feel you just can't beat the best at the big tournaments, so it's wise and worthwhile to take the extra week, extra month maybe.

"I'm sure Andy is going to have a lot of years left, so he shouldn't hurry, but as a professional athlete you always want to come back as quick as possible. You need to have goals but sometimes they need to be postponed."