Barbora Krejcikova has criticised “unprofessional commentary” regarding her appearance on the US TV network Tennis Channel.

The Wimbledon champion was taking part in the WTA Finals in Saudi Arabia this week, the culmination to the regular women’s season, where she lost to Zheng Qinwen in the semi-finals on Friday.

Apparently not aware he was on air, Jon Wertheim, a prominent American tennis journalist, said of Krejcikova: “Who do you think I am? Barbora Krejcikova? Look at the forehead when Krejcikova and Zheng take the court.”

The clip was circulated on social media, and in response the Czech wrote on X: “You might have heard about the recent comments made on Tennis Channel during the WTA Finals coverage that focused on my appearance rather than my performance.

“As an athlete who has dedicated herself to this sport, it was disappointing to see this type of unprofessional commentary. This isn’t the first time something like this is happening in sports world.

“I’ve often chosen not to speak up, but I believe it’s time to address the need for respect and professionalism in sports media. These moments distract from the true essence of sport and the dedication all athletes bring to the field.

“I love tennis deeply, and I want to see it represented in a way that honours the commitment we make to compete at this level.”

Following Krejcikova’s comments, Wertheim also took to X to apologise.

“During a Tennis Channel studio show on Friday, I made some deeply regrettable comments off-air,” he wrote. “I acknowledge them. I apologise for them. I reached out immediately and apologised to the player.

“I joined the show by Zoom. In rehearsal we were shown a graphic of a player who had just competed. It showed her at an angle that exaggerated her forehead. A few minutes later, I was told to frame up my Zoom. I looked at the low camera angle and joked that it made my forehead resemble the player in question.

“Someone in the control room chimed in and I bantered back. Though this was a private rehearsal, this exchange inadvertently, and without context, made it to live air.

“I realise: I am not the victim here. It was neither professional nor charitable nor reflective of the person I strive to be. I am accountable. I own this. I am sorry.”

It is not the first time a broadcaster has been criticised for comments made about a female tennis player’s appearance.

In 2013, the BBC apologised after presenter John Inverdale said of French player Marion Bartoli after she had won Wimbledon: “Do you think Bartoli’s dad told her when she was little: ‘You’re never going to be a looker, you’ll never be a (Maria) Sharapova, so you have to be scrappy and fight’?”