Naomi Osaka faces expulsion from the French Open and future Grand Slams if she continues to refuse to speak to the media.
Japan's Osaka said last week she will not give any news conferences during the French Open because she wants to protect her mental health.
She was fined US $15,000 for not doing media after Sunday's first-round win over Romania's Patricia Maria Tig.
A joint statement from the four Grand Slam organisers said Osaka also faces "more substantial fines and future Grand Slam suspensions".
Later on Sunday, Osaka tweeted "change makes people uncomfortable".
[Source: BBC]
