Roger Federer is withdrawing from the Australian Open while he continues preparing to return to action after two operations on his right knee, his agent told The Associated Press on Sunday.

Tony Godsick -- Federer's longtime representative and CEO of their management company, TEAM8 -- said he is working on putting together a 2021 tennis calendar for the 20-time Grand Slam champion, who plans to get back on tour soon after the year's first major tennis tournament.

"Roger has decided not to play the 2021 Australian Open. He has made strong progress in the last couple of months with his knee and his fitness. However, after consultation with his team, he decided that the best decision for him in the long run is to return to competitive tennis after the Australian Open," Godsick said in a statement released to the AP.

"I will start discussions this coming week for tournaments that begin in late February and then start to build a schedule for the rest of the year," Godsick said.

The start of the Australian Open's main draw was delayed by three weeks because of the coronavirus pandemic and is now scheduled to begin on Feb. 8 at Melbourne Park.

Federer, 39, has spent more weeks atop the ATP rankings than anyone else but is No. 5 after his hiatus. He is currently training in his usual offseason home of Dubai, United Arab Emirates.

The choice to delay his comeback came with input from coaches Severin Luthi and Ivan Ljubicic and fitness coach Pierre Paganini.

Federer hasn't played a tournament match since late January at the 2020 Australian Open, where he was clearly injured while losing in straight sets to eventual champion Novak Djokovic in the semifinals. Soon after, Federer played in an exhibition charity event with Rafael Nadal in front of a record tennis crowd of more than 50,000 people at a soccer stadium in Cape Town, South Africa.

Just weeks later, Federer announced he had arthroscopic surgery on his right knee and would be sidelined for at least four months. He later had a second procedure on that knee and wound up missing the rest of the pandemic-altered season.

One measure of Federer's popularity: Despite appearing in only six matches in 2020, he recently was voted the winner of the ATP Tour fans' favorite award for the 18th consecutive time.

Until this knee issue, Federer only had his career interrupted once by an operation -- on his left knee in 2016. He sat out the second half of that season, including the Rio de Janeiro Olympics and the US Open, but was back at his best when he resumed playing, winning the Australian Open and Wimbledon in 2017.

He won the Australian Open again the following year for his sixth trophy there, to go along with eight from Wimbledon, five from the U.S. Open and one from the French Open to complete a career Grand Slam.

While Federer was sidelined this year, Nadal equaled his men's record for most major championships by collecting his 20th at Roland Garros in October. Federer posted a congratulatory message on social media to Nadal that day, saying he hopes "20 is just another step on the continuing journey for both of us.''

Djokovic's title in Australia this year moved him closer to the other members of the Big Three of men's tennis with a total of 17.