Rafael Nadal and other leading players at the Rolex Monte-Carlo Masters face a nervous wait after world number two Daniil Medvedev tested positive for coronavirus.
The announcement came ahead of the third day of play at one of the ATP's biggest events, with Medvedev replaced in the draw by Argentinian lucky loser Juan Ignacio Londero.
Medvedev said in a statement: "It's a big disappointment not to play in Monte-Carlo.
Britain's Dan Evans, who beat 2019 runner-up Dusan Lajovic 6-3 6-7 (11) 6-2 for his first tour-level victory on clay for four years, said: "It's definitely in mind I'm very eager to get vaccinated, if I can. It would be heart-breaking if I tested positive for Wimbledon.
"It's very important to stick to the protocols in place. If some people are being blase, then it ruins it for everybody else because if one person tests positive, this virus, it can go round very quickly.
"So seeing scenes in England yesterday, I won't be socialising any time soon."
Fourth seed Stefanos Tsitsipas became the first player to reach the third round, beating fellow Australian Open semi-finalist Aslan Karatsev 6-3 6-4.
Spaniard Alejandro Davidovich Fokina joined him, securing a first top-10 win by beating eighth seed Matteo Berrettini 7-5 6-3.
Miami Open runner-up Jannik Sinner will play world number one Novak Djokovic for the first time after a 6-3 6-4 victory over Albert Ramos-Vinolas.
Nineteen-year-old Sinner was one of five Italian winners on Tuesday. Defending champion Fabio Fognini defeated Miomir Kecmanovic 6-2 7-5 while Salvatore Caruso, Lorenzo Sonego and Marco Cecchinato also reached round two.
Felix Auger-Aliassime's partnership with Toni Nadal – uncle and former coach of Rafael – got off to a losing start as the young Canadian was beaten 7-6 (3) 6-1 by Cristian Garin having led 4-2 overnight.
"I'm very lucky to be able to learn from him and benefit from his experience and work with him," said the 20-year-old. "Of course, there's a lot of work to do, but it's a good association and I'm very happy."
Miami champion Hubert Hurkacz continued his winning run with a 6-3 3-6 6-3 win against another Italian, Thomas Fabbiano, ninth seed Roberto Bautista Agut and 14th seed Grigor Dimitrov were straight-sets winners and 17-year-old Dane Holger Rune was beaten 6-2 6-1 by Casper Ruud.
