Roger Federer's coach, Severin Luthi, says the Swiss star could play in a warm-up tournament prior to the 2021 Australian Open as he works his way back to full fitness.

The 20-time Grand Slam winner underwent knee surgery in February and was expected to make his return in June, but a setback forced him to undergo a second operation.

He was eventually forced to call an early end to his 2020 campaign, but vowed to return to the ATP Tour next year.

His long-term coach says his rehabilitation remains on track and the Swiss great is scheduled to start practising soon.

"Roger is fine. He's very good, but that's not surprising when you know how he always sees the positive side of things," he told reporters during the launch of the 1st Pro Cup exhibition tournament in Biel, Switzerland.

"He has resumed physical training with Pierre Paganini. The next step will be mid-August, he'll start practising again."

Federer's last competitive tournament was the 2020 Australian Open and he has pencilled in the Melbourne Grand Slam as his return event, but he could still return to action sooner.

"We are sticking to what was decided. He'll come back for the Australian Open 2021 if it takes place," Luthi said.

"However, we are considering whether to play a tournament just before Melbourne."

- TEAMtalk media