Federer to lay low ahead of Open

Roger Federer will be laying low until the Australian Open to rid himself of a nagging sickness, but says he's in no doubt he'll be in grand slam form come the tournament's start.

Defending champion Federer was upset 6-4 6-4 by Milos Raonic on Sunday night in the final of the Brisbane International, with the Swiss veteran surprisingly off-colour and unable to contain the big-serving Canadian.

Federer played at a limited capacity in Brisbane, his only Open lead-up tournament, due to a flu bug that swept through his family and threatened to sideline the event's biggest drawcard.

Indeed, if it was played over five sets, Federer said earlier in the week, he probably would have withdrawn from the event.

But after playing four days in a row, the 34-year-old says he will take a much-needed break to shake off what's left of the illness, and believes his base fitness will hold him in good stead as he looks ahead to Melbourne, where he will continue his chase for a first grand slam title since Wimbledon in 2012.

"I've still got a cough and the throat is a bit weird," Federer said.

"Definitely got to make sure I get over it as quickly as possible.

"As long as I keep on playing and doing all that stuff it's not going to go away faster."

Raonic, meanwhile, has emerged as a genuine Australian Open contender after his victory over Federer, just the second time he has been able to best the 17-time grand slam winner in his career.

The world No.14 said he "definitely" has it in him to become a force at the majors this year.

"It's sort of two steps: being able to step up and play great for two weeks, which I believe I can definitely do."

But Raonic said if he wanted to compete to be the best player in the world, that was about playing well for 30 weeks.

"That's maybe another step away, but I definitely feel I have it within myself to step up with play great tennis for two weeks."