French tennis authorities are planning for up to to 60 per cent capacity when the revised Roland Garros tournament starts in September.
French federation president Bernard Giudicelli told a news conference in Paris that on the main courts, a maximum of four people could sit together with an empty seat between groups.
On the other courts, one seat out of two will be empty when the main tournament starts on September 27.
He explained that it meant about 20,000 spectators are expected during the early stages of the two-week claycourt Grand Slam, and about 10,000 on the day of the final.
Those numbers could change if the French government revises its social distancing rules.
Hygiene protocols for players and support teams will be announced later.
The French Open was postponed from its usual May-June dates to September due to the COVID-19 pandemic. The US Open is being held without any spectators in attendance in New York from August 31 to September 13.