Roger Federer has fallen outside the world's top 10 for the first time since 2002 but he could still win another grand slam title, according to former world No.1 Stefan Edberg.

While Andy Murray's rise to world No.1 was the main talking point of Monday's new ATP rankings, 17-times major champion Federer's slide to 16th was largely overlooked.

The Swiss ended his season in July in a bid to recover fully from knee surgery, although he aims to be fit for the Australian Open in January.

But logic suggests 35-year-old Federer's days of challenging for silverware might be numbered. His last grand slam title came at Wimbledon in 2012.

But Edberg, who has coached Federer, disagrees.

"I thought in the past years he would have won one, he was so close," six-times major champion Edberg, 50, told Tennis World.

"It becomes even tougher, he is not young any more but there is still hope. If there's one who can do it, it's Roger.

"But it will be an emotional challenge for him to come back next year."