Roger Federer cast doubt on his immediate return to tennis during an awards ceremony Sunday where he was being honored as Switzerland's greatest athlete of the past 70 years.

The 20-time major champion, who has been sidelined since February with a right knee injury, had previously targeted the 2021 Australian Open as his return to competitive play.

"I would have hoped that I would be at 100 percent by October," Federer said, according to Swiss news outlet SRF. "But I still am not [100 percent] today. It will be tight for the Australian Open. I wish I was further along, but at the same time I'm satisfied with where I am at the moment."

Federer, 39, last played in the semifinals at the 2020 Australian Open, losing to eventual champion Novak Djokovic in straight sets. He underwent a procedure on his knee in February, and then a second one in June following complications. He announced he would not be able to play when the season resumed in August.

Due to the adjusted ranking system, he finished the year ranked No. 5 in the world.

The 2021 Australian Open is expected to begin Feb. 8, three weeks later than originally scheduled, and players will reportedly have to arrive to Melbourne between Jan. 15-17 in order to complete a 14-day quarantine.

Federer is a six-time champion at the event.

While Federer gave no indication he was ready to retire, he did suggest there was a chance he might not be able to play again.

"I stand here tonight with an incredibly good feeling and share that with all of you," he said while accepting the award. "I hope that there will be something to see with me next year. If not, then that's an unbelievable end point."

In an interview earlier this month with fellow player Kei Nishikori, Federer said one of his goals was to play in the Olympic Games in Tokyo next summer.

"Obviously the big plan is to be there for the Olympics," Federer said. "This is for me, the big one. Maybe selfishly for me, it has not been a bad thing that it was moved a little bit because of the problems I had last year. ... Let's hope for the best for the Olympic Games coming to Tokyo this next year. This is clearly also one of my big goals. I really hope I can come back to Tokyo and Japan for that."