All players at the French Open starting later this month will be housed in two designated hotels "without exception" to reduce the risks from coronavirus, tournament director Guy Forget said on Monday.
Forget also announced that just 11,500 spectators a day will be admitted instead of the 20,000 they were originally hoping to accommodate during the September 27-October 11 tournament.
Current French government law limits public gatherings to 5,000.
The Roland Garros complex will be divided into three separate zones "independent of one another" and corresponding to each of the main showcourts, with no crossing in-between.
Courts Philippe Chatrier and Suzanne Lenglen will be limited to 5,000 spectators apiece with Simonne Mathieu restricted to just 1,500. No tickets will be sold for the outside courts.
In total, fewer than 150,000 fans are expected over the course of the 15 days -- just over a quarter of the 520,000 who attended the 2019 edition.
Players will be tested "upon their arrival and will receive their accreditation as soon as the first negative test is returned", said Forget.
A second test will be carried out within 72 hours and then another every five days based on a player's progression in the tournament, he added.
French tennis federation director-general Jean-Francois Vilotte said: "We are not thinking in terms of an airtight sanitary bubble, it's a fantasy.
"What we're putting in place, it's to completely minimise the risks," he continued.
"But the principle of responsibility is respect towards everyone and for the social distancing measures. It's the only way to protect one's health and the health of those we come across."
Players will only have access to the tournament site on the days of their matches. They will be confined to practice courts at the nearby Jean Bouin club the rest of the time.
Strict regulations are also in force at the spectator-free US Open, with only players, officials and a handful of media permitted inside the New York venue.
Players are being kept in a tightly controlled environment to minimise the risk of Covid-19 infection and are being tested for coronavirus regularly throughout the tournament.
The men's draw was disrupted on the eve of the tournament when France's Benoit Paire was removed after organisers announced that an unidentified player had been withdrawn after testing positive for the virus.
Several players in contact with Paire were subsequently forced to adhere to stricter safety measures.
Most competitors are staying at specific hotels and are not allowed to travel anywhere other than to and from the tournament site and their accommodation.
However, some players have rented private houses that must be guarded 24 hours by security to safeguard the quarantine bubble.