Tennis star, Naomi Osaka fired back Sunday after she was fined $15,000 for skipping a mandatory press conference following her first-round victory at the French Open.

Tournament organizers said Osaka was fined for failing to “honor her contractual media obligations.”

Osaka announced that she would not participate in any media events in a post last week. The 23-year-old cited mental health concerns as the reason for her decision.

Osaka acknowledged the likelihood of a fine in her initial post, expressing hope that “the considerable amount that I get fined for this will go towards a mental health charity.”

Osaka, a four-time Grand Slam tournament winner, addressed the fine in a tweet after her 6-4, 7-6 (4) victory over 63rd-ranked Patricia Maria Tig on Sunday.

“Anger is a lack of understanding,” Osaka tweeted. “Change makes people uncomfortable.”

In a lengthy statement addressing the fine, the organizers of the French Open said they had urged Osaka to reconsider her decision ahead of the tournament.

The officials warned that Osaka could face additional penalties, including disqualification from tournaments, if she continued to skip press conferences.

“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,” the officials said.

The organizers said the mental health of competitors was “of the utmost importance to the Grand Slams,” adding the disciplinary action was meant to ensure fairness.

“We want to underline that rules are in place to ensure all players are treated exactly the same, no matter their stature, beliefs or achievement,” the statement said. “As a sport there is nothing more important than ensuring no player has an unfair advantage over another, which unfortunately is the case in this situation if one player refuses to dedicate time to participate in media commitments while the others all honour their commitments.”