Wimbledon champion Barbora Krejcikova criticised a journalist's "unprofessional commentary" after he made a remark about her appearance on air.

During a Tennis Channel broadcast on Friday, Jon Wertheim commented on the Czech world number 13's forehead.

Krejcikova was competing at the WTA Finals in Riyadh, Saudi Arabia, where she was knocked out in the semi-finals by eventual runner-up Zheng Qinwen.

Wertheim said his comments were "deeply regrettable" and that he apologised to Krejcikova.

"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," 28-year-old Krejcikova posted on X., external

"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 [the] 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 honors the commitment we make to compete at this level."

In a statement on Sunday, Wertheim said he made the comments in a rehearsal that was "inadvertently" broadcast.

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

"What happened? 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 moments 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 photo of 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."

BBC Sport has contacted the Tennis Channel for comment.