Swiss tennis star Roger Federer has pulled out of the Australian Open tournament as he is still working on his fitness after two knee operations earlier this year, his agent said.

The 39-year-old Federer, who has won 20 grand slam tournaments in his career, last played at the Australian Open in January this year after which he had to go in for a knee surgery.

“Roger has decided not to play the 2021 Australian Open,” his agent Tony Godsick said in a statement. “He has made strong progress in the last couple of months with his knee and his fitness.

Federer had earlier said that the three-week delay in the calendar of the Australian Open, which is now scheduled to start on February 8, would help him to recover in time for the tournament. The tournament was delayed due to restrictions that have been imposed to contain the spread of the Covid-19 pandemic.

“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,” his agent said.

Godsick disclosed that he would be preparing a playing calendar for Federer from the end of February onwards.

“In the end Roger ran out of time to get himself ready for the rigours of a Grand Slam and he’s very disappointed he won’t be coming to Melbourne in 2021,” Australian Open tournament director Craig Tiley said in a statement. “We wish him all the best as he prepares for his comeback later in the year and look forward to seeing him in Melbourne in 2022.”

Federer has made it to the semi-finals of the Australian Open 15 times in his playing career and won the title six times, the last in 2018. He had Federer made the semis earlier this year, losing to eventual winner Novak Djokovic..