"I can still not run. But I'm working daily in the gym," the 40-year-old Federer said at a sponsor's event on Wednesday.

"I really hope that I can put weight on my knee again in two to three weeks.

"Then we'll see how the body reacts so we can hit the ball again in April or May."

The long-time former men's world No.1 had a third knee operation last August and has not played since a quarter-final loss at Wimbledon in 2021.

"Of course I wish that everything could go quicker," said Federer. "But the doctors don't want me to overdo everything."

Federer has won 20 grand slams which was a joint record until Spanish rival Rafael Nadal won the Australian Open last weekend for his 21st major, prompting the great Swiss to congratulate him.

Australian Associated Press