Pressure is mounting on four-time grand slam champion Naomi Osaka as she faces expulsion from the French Open for not adhering to an obligation by players to face a news conference after her match.

World No.2 Osaka was fined $US15,000 ($19,500) for refusing to fulfil obligatory media commitments at Roland Garros after a 6-4 7-6 (7-4) first-round Open victory over Patricia Maria Tig, citing mental health reasons.

The decision did not down well with the tournament directors, who issued a statement threatening her with severe sanctions including expulsion if she didn’t reconsider her stance.

“The Roland Garros teams asked her to reconsider her position and tried unsuccessfully to speak with her to check on her well-being, understand the specifics of her issue and what might be done to address it on site…” a statement read.

“As might be expected, repeat violations attract tougher sanctions including default from the tournament.”

Naomi Osaka is interviewed on court after winning her First Round match against Patricia Maria Tig of Romania. Photo: Getty

In a cryptic post on social media on Sunday night local time, the 23-year-old Japanese star wrote “anger is a lack of understanding. change makes people uncomfortable”.

Her sister Mari weighed into the controversy on Reddit to explain her silence before deleting the post, realising she “f–ked up” and probably made the situation worse for the champion player.

She wrote: “So it’s a little hard for me to see all these different opinions from everyone and not being able to share Naomi’s side, even just a little bit,” Mari’s now-deleted post read.

“She sucks at explaining her actions most of the time and she’s playing a grand slam so there’s even less of a chance that she will take her time to dwell and explain something that she doesn’t even want to think about.”

Tweet from @BenRothenberg

Mari then posted: “My words are probably coming across so horribly to a lot of people who think taking care of mental health is strategic”.

“I’m sorry Naomi I probably made the situation worse.”

Tennis players divided

While it gave some insight into Osaka’s motivation, her decision to not front the press has divided the tennis world, with past and present players reinforcing the importance and reasons for the post-match press conferences.

The 2019 French Open champion Ash Barty said “press is kind of part of the job”.

“We know what we sign up for as professional tennis players. … At times, press conference are hard, of course, but it’s also not something that bothers me. …

“For me, personally, it doesn’t keep me up at night what I say and hear or what you guys ask me. So I try and make it a little bit lighter and have a bit of fun with you guys,” Barty said.

Past champion Billy Jean King said she was “torn” by Osaka’s decision, but said the media still played an important role in telling the stories of female tennis players.

Tweet from @BillieJeanKing

Despite her media snub, Osaka did take part in a short and rather awkward on-court interview for the few hundred fans allowed into Court Philippe Chatrier after her victory over Romanian Tig.

“I’m very glad that I won,” said Osaka, who skipped the tournament last year after winning her third slam title at the US Open.

“It’s a very beautiful court. I’ve only played two matches here, one was before the roof and one is right now. Hopefully I’ll keep it going.”

Osaka, who lives in Florida, has never made it past the third round at Roland Garros and arrived in Paris having played only three matches on clay this season after early defeats in Madrid and Rome.