Naomi Osaka was fined $15,000 by tennis' Grand Slam organisers on Sunday and warned of possible ejection from the French Open and suspension from future majors after the world number two skipped a news conference after her opening win at Roland Garros.

The 23-year-old, a four-time Grand Slam winner, cited the impact on players' mental well-being for her decision ahead of the claycourt major not to hold news conferences, saying the nature of questions from journalists is like "kicking a person when they are down".

Osaka started her French Open campaign with a win over Romanian Patricia Maria Tig 6-4 7-6(4) and then boycotted the post-match news conference, although she did hold a court-side interview immediately after the game.

The board of the four Grand Slams said in a statement on Sunday that the French Open organisers had asked Osaka to reconsider her position and tried unsuccessfully to speak with her to resolve the matter.

"The Australian Open, Roland-Garros, Wimbledon and the US Open jointly wrote to her to check on her well-being and offer support, underline their commitment to all athletes' well-being and suggest dialog," the statement read.

"She was also reminded of her obligations, the consequences of not meeting them and that rules should equally apply to all players.

"Naomi Osaka today chose not to honour her contractual media obligations. The Roland-Garros referee has therefore issued her a $15,000 fine."

Osaka's management did not immediately respond to a request for comment.

The Japanese player, who lives in Florida, has never made it past the third round at Roland Garros and arrived in Paris with only three matches under her belt on clay after early defeats in Madrid and Rome.

After American great Serena Williams, Osaka commands the highest profile of any female tennis player, and the Women's Tennis Association said it would also welcome dialogue with her regarding her news conference boycott.

Osaka, who according to sports business website Sportico earned $55.2 million over the past 12 months, has in the past used her platform and considerable media attention to highlight issues of police violence and racial inequality.

While announcing her decision on Twitter to boycott news conferences she said she hoped the "considerable amount" that she expected to forfeit as fines would go towards a mental health charity.

Rafa Nadal, a 20-times Grand Slam winner, and women's world number one Ash Barty have said they believe players have a duty to address the media.

Seven-time Grand Slam singles champion Mats Wilander said on Sunday that Osaka should not play tournament tennis until she is ready to take part in post-match news 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 board said.

"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."

Osaka showed no signs of being distracted by the issue during her opening match on a sun-bathed Philippe Chatrier court, however.

Asked in her courtside interview about how she adapts her game to the surface, Osaka said: "It's a work in progress. Hopefully the more I play the better I play."

"I'm really glad that I won. It's a beautiful court. I've only played two matches here (on Philippe Chatrier), one before the roof and one now, so hopefully I'll keep it going."

The 23-year-old Osaka, who missed last year's tournament due to a hamstring problem, was not keen on engaging in long rallies and seemed too powerful against the 63rd-ranked Tig.

She stamped her authority on the match early with a 5-2 lead but needed a second break of serve after the Romanian staged a late fightback.

Tig saved a breakpoint and a matchpoint to take the second set into a tiebreaker before Osaka sealed it with a backhand winner to set up a second round meeting with another Romanian in Ana Bogdan.