Cape Town - Daniil Medvedev has escalated his developing feud with Stefanos Tsitsipas, who criticised his playing style last week.
Tsitsipas lost to Medvedev in Shanghai last week, taking his head-to-head record to 0-5 against him, and it clearly irked him.
"I don't mean to be rude at all, actually, at all, but it's just boring," Tsitsipas said after their meeting in Shanghai.
"It's boring. So he has a huge serve, and if you manage to get it back, it's just countless balls inside the court."
Medvedev, though, has bitten back. Asked about Tsitsipas' comments he said that he can't take him seriously, particularly after the childish way in which he believes the Greek behaved after the Laver Cup.
"Someone told me about this yesterday, so I read in more detail this morning.
"I had a lot of thoughts. I will say only one thing: after his interview in Shanghai, where he told how they celebrated the victory in the Laver Cup, it is difficult to take him seriously.
"Just to quote: he said that he was forced to drink there, and that was disgusting.
"Okay, that's okay. But the most important thing: 'Mom, you hear, it was disgusting! I can provide you a video.' This is ridiculous. I can no longer take him seriously."