Miami, March 2  : Defending champion Roger Federer has withdrawn from this month’s Miami Open as he works his way back to full fitness following surgeries to repair his right knee.

The 39-year-old Swiss star, who has not played since losing in the semi-finals of last year’s Australian Open, is due to make his return from a year-long layoff at the Qatar Open in Doha next week.

However the Miami Herald cited Federer’s agent Tony Godsick as saying on Monday that the 20-time Grand Slam singles champion had opted to skip the Miami tournament for scheduling reasons.

The Herald said Federer could play in Dubai after Doha but would then take a training break.

Federer’s withdrawal is a blow to organizers of the Miami tournament, who were forced to cancel last year’s event as Covid-19 chaos left sport in North America at a standstill.

The pandemic has already impacted the 2021 calendar, delaying the Australian Open and forcing the Indian Wells tournament in California — the traditional lead-in to the Miami Open — out of its usual slot in March.

Miami is still expected to feature a strong field despite Federer’s withdrawal, with world number one Novak Djokovic and 20-time Grand Slam-winner Rafael Nadal confirmed for the men’s draw.

Serena Williams and newly minted Australian Open champion Naomi Osaka are also slated to appear in the women’s draw.