World number two Daniil Medvedev has withdrawn from the Monte Carlo Masters after testing positive for coronavirus.
The Russian has been placed in isolation and will be monitored by the tournament physician.
Second seed Medvedev had a first-round bye for the clay-court tournament, which began on Monday.
“My focus now is on recovery and I look forward to getting back out on tour as soon and as safely as possible,” the 25-year-old said.
Medvedev practised with world number three and 11-time Monte Carlo champion Rafael Nadal on Monday.
The Monte Carlo Masters takes place from 12-18 April.