Naomi Osaka’s decision to boycott press conferences at Roland Garros was blasted as a “phenomenal error” by the head of French tennis on Thursday who said the Japanese star’s move was “unacceptable”.

World No 2 Osaka said she will not take part in any media duties at the French Open which starts on Sunday.

The 23-year-old said she was concerned by the effect of news conferences on her mental health which she likened to “kicking a person while they’re down”.

However, French Tennis Federation president Gilles Moretton lambasted Osaka, a four-time Major winner.

“It is a phenomenal error and it shows to what extent it is necessary to have strong governance,” he said. “What is happening is not, in my opinion, acceptable. It is tennis we want to promote.”

Osaka will likely be fined up to $20,000 for every news conference she skips. However, that will cause little financial impact – in 2020, she made $37 million, more than any other female athlete.

Osaka said she will donate any fines to mental health charities.

“I have often felt that people have no regard for athletes’ mental health and this rings true whenever I see a press conference or partake in one,” Osaka said on Twitter.

“We’re often sat there and asked questions that we’ve been asked multiple times before or asked questions that bring doubt into our minds and I am not going to subject myself to people who doubt me.”

Under tennis tournament rules, all players are required to hold press conferences after each match. They also perform media duties before a tournament.

Osaka regularly packs out media rooms because of her standing in the sport and her charisma.

She fields questions in Japanese and English and is regarded as one of the world’s most marketable stars.

She added on Wednesday: “I believe the whole situation (of news conferences) is kicking a person while they are down and I don’t understand the reasoning behind it.”

French Open tournament director Guy Forget said he was stunned by Osaka’s decision which he found at odds with a tournament still facing organisational challenges posed by the ongoing pandemic.

“As the tournament progresses, we will see how she behaves. I don’t know what her attitude will be in the coming days, but it doesn’t send a very positive message,” said Forget.

Osaka has yet to get beyond the third round at Roland Garros.