French Open organisers announced on Wednesday evening that a men's doubles pair had both tested positive for coronavirus and been withdrawn from the tournament.
Tournament organisers did not name the players.
Spanish duo Feliciano Lopez and Jaume Munar, who had been due to face Pablo Andujar and Pedro Martinez in the first round on Thursday, were replaced in the draw and order of play by alternates.
Meanwhile, Croatian top seeds Mate Pavic and Nikola Mektic, who would have been strong favourites for the title, were replaced in the original draw by Andujar and Martinez.
The French tennis federation said Wednesday night that these were the first two positives from the 2,446 coronavirus tests that have been administered on players and their entourages since the start of qualifying rounds on May 24.
"The Roland-Garros tournament organisers confirm that two players from the men's doubles draw, on the same team, have tested positive for COVID-19," a statement read.
"In line with the tournament's public health and safety protocol, the pair have been removed from the draw, which commenced yesterday, and the two players placed in quarantine... This is the first occurrence in which the tournament organisers must remove players, in accordance with their health protocol."