The number of fans allowed into the French Open has been cut to 1,000 per day after new coronavirus restrictions were imposed by the French government.
The French Tennis Federation said it "deeply regrets" the new restrictions.
The clay-court Grand Slam, which starts on Sunday, had originally been set to welcome around 11,500 fans each day before that number was cut to 5,000 last week amid rising Covid-19 cases.
The event is usually in May-June but was postponed because of the pandemic.
Around 35,000 fans usually attend Roland Garros - a 12-hectare site with 16 courts - every day in the first week.
The new restrictions mean there will be a daily draw to decide which ticket holders are allowed in.
Those who are not selected will be refunded and given priority access to tickets for the 2021 event.
"From the very outset of the public health crisis that our country is experiencing, the French Tennis Federation has consistently worked closely with government departments, to determine how to organise the tournament in the current situation," said the organisers.
"It deeply regrets these new restrictions."
Spanish great Rafael Nadal will be seeking a record-extending 13th French Open singles title, which would also bring him level with Switzerland's Roger Federer on 20 Grand Slam singles titles.
The recent US Open was held behind closed doors in New York.