The Association of Tennis Professionals (ATP) has confirmed the withdrawal of world number two Daniil Medvedev from the Monte-Carlo Masters after testing positive for coronavirus.
The Russian had been training with 11-time champion Rafael Nadal of Spain yesterday only to test positive just hours later.
But Nadal has been given the all-clear to begin his campaign in the ATP Masters 1000 event as he prepares to make his first appearance since losing in the Australian Open quarter-finals in February.
The ATP revealed that Medvedev had been moved into isolation where he will be monitored by its medical team.
"It’s a big disappointment not to play in Monte-Carlo," he said.
"My focus is now on recovery and I look forward to getting back out on Tour as soon and as safely as possible."
Nadal is set to meet Argentina’s Federico Delbonis, who beat Frenchman Adrian Mannarino 7-5 6-1 at the Monte Carlo Country Club today.
"Nadal is absolutely fine," Benito Perez-Barbadillo, publicist for the 20-time Grand Slam champion, told Reuters.
"As we understand the virus does not anyway show before three-four days.
"The next scheduled testing is in three days."
Italian teenager Jannik Sinner who reached the final of the Miami Open booked a blockbuster meeting with world number one Novak Djokovic of Serbia.
Making his Monte-Carlo Masters debut, Sinner recovered from a slow start to defeat 2017 finalist Albert Ramos-Vinolas of Spain 6-3, 6-4.
It will be the first ATP Tour meeting between Sinner and Djokovic, with the Serbian set to compete for the first time since he captured a ninth Australian Open title.
Sinner was one of five Italians to reach the second round today.
Defending champion Fabio Fognini moved past Serbia's Miomir Kecmanovic 6-2, 7-5, while there were also wins for Lorenzo Sonego, Marco Cecchinato and Salvatore Caruso.
Sonego defeated Hungary’s Marton Fucsovics 6-3, 6-4 to extend his unbeaten record on clay this year to 5-0 and advance to the second round where he is due to face Germany’s Alexander Zverev.
Cecchinato converted five of his nine break points to beat German qualifier Dominik Koepfer 6-4, 6-3, while Caruso came from behind to beat Monegasque wild card Lucas Catarina 6-7, 7-6, 6-3 in over three hours.
Miami champion Hubert Hurkacz of Poland needed three sets to complete his two-day encounter against Italy’s Thomas Fabbiano on 6-3, 3-6, 6-3.
The 13th seed is scheduled to meet Dan Evans for a place in the third round after the British number one saw off 2019 runner-up Dusan Lajovic of Serbia 6-3, 6-7, 6-2.
Fourth seed Stefanos Tsitsipas of Greece claimed a 6-3, 6-4 victory over Aslan Karatsev to progress to the third round.
Tsitsipas awaits the winner of Australian John Millman and Chilean 16th seed Cristian Garin for a spot in the quarter-finals.
Garin defeated France’s Felix Auger-Aliassime in a rain-interrupted 7-6, 6-1 first-round clash, while the Millman advanced after a 6-3, 6-3 victory over Frenchman Ugo Humbert.
Elsewhere, Norwegian Casper Ruud won a Scandinavian showdown against Danish wild card Holger Vitus Nodskov Rune 6-2, 6-1, while Spanish ninth seed Roberto Bautista Agut downed American Taylor Fritz 6-2, 7-5.