World number two Naomi Osaka faces expulsion from the French Open if she continues to refuse to speak to the media, Grand Slam organisers said.
Japan’s Osaka said last week she will not give any news conferences during the Grand Slam because she wants to protect her mental health.
She was fined $15,000 (£10,570) for not doing media after her first-round win against Romania’s Patricia Maria Tig on Sunday.
The second seed won 6-4 7-6 (7-4).
A joint statement from the four Grand Slam organisers said Osaka also faces “more substantial fines and future Grand Slam suspensions”.
They added that following her announcement, Roland Garros teams asked the 23-year-old to reconsider her position and were unsuccessful in their attempts to check on her wellbeing.
After a “lack of engagement” from Osaka, the Grand Slam organisers wrote to her to offer support, as well as to “remind her of her obligations”.
“A core element of the Grand Slam regulations is the responsibility of the players to engage with the media, whatever the result of their match, a responsibility which players take for the benefit of the sport, the fans and for themselves,” the statement said.
“We have advised Naomi Osaka that should she continue to ignore her media obligations during the tournament, she would be exposing herself to possible further Code of Conduct infringement consequences.
“As might be expected, repeat violations attract tougher sanctions, including default from the tournament and the trigger of a major offence investigation that could lead to more substantial fines and future Grand Slam suspensions.”
It added that the rules exist “to ensure all players are treated exactly the same”.
Osaka had earlier moved to put the controversy to one side as she started her campaign in Paris with a straight-set win over Tig.
She hit 20 winners in a largely dominant first set on Court Philippe Chatrier, but had to work even harder in the second before her quality came through in the tie-break.
The four-time major champion plays another Romanian, Ana Bogdan, next.
Osaka has not yet reached the same heights on the red dirt that she has on hard courts, having never progressed past the third round at Roland Garros and holding a win-loss record of 13-13 in the events leading up to the Grand Slam.
More to follow.