Alexander Zverev has been picked up on court-side microphones seemingly poking fun at Naomi Osaka's media boycott at the French Open.
Osaka copped a $15,000 fine on Sunday after skipping her post-match press conference following her first-round victory over Patricia Maria Tig.
'WHAT THE HELL': Tennis fans stunned by 'crazy' French Open drama
'HARD TO WATCH': French Open rocked by 'sad' Dimitrov moment
Before the tournament got underway, the World No.2 said she won't be attending any press conferences at Roland Garros because of the detrimental affect they can have on her mental health.
Osaka's boycott has heavily divided the tennis world, with a number of fellow players speaking out against her stance.
And things took a seemingly nasty turn on Sunday when Zverev appeared to mock Osaka before his first-round match.
Walking onto the court for the coin toss before his win over Oscar Otte, Zverev was informed by chair umpire Louise Azemar Engzell that he was late.
The German then responded by referencing Osaka.
“You know how Naomi said you could fine her for every single match she is not at the press conference?" he responded.
“You can fine me for every single match I’m late.”
Needless to say the cheeky moment didn't go down particularly well with fans.
Naomi Osaka facing disqualification from French Open
After copping the $15,000, Osaka was warned by the Grand Slam board that she faces being thrown out of the French Open should she continue her boycott.
Osaka's controversial move prompted a joint statement from the board of the four grand slams, who threatened Osaka with severe sanctions should she not reconsider her stance.
"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 statement read.
"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.
"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.
"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.
"Finally, all grand slams remain committed to continually reviewing and discussing opportunities, together with the tours and the players, to improve every aspect of the player experience, including with the media.
"But we consider this is only ever achieved through respectful and constructive discussions."
In an apparent response on Twitter, the Japanese star wrote: "Anger is a lack of understanding. Change makes people uncomfortable."
Despite her media snub, Osaka did take part in a short on-court interview on Court Philippe Chatrier after her victory over Tig.
Click here to sign up to our newsletter for all the latest and breaking stories from Australia and around the world.