Berrettini and Kyrgios have not clashed publicly but the No 23 seed in New York has plenty of previous with Ruud.
Should that semi-final be etched in the diary it would be only their third career meeting.
Their first meeting was the most controversial with Ruud progressing at the 2019 Italian Open in Rome after Kyrgios was defaulted in a deciding set.
At 1-1 in the third, Kyrgios was handed a game penalty for unsportsmanlike conduct and, as he so often did in that time, he did not take it well.
Kyrgios broke a racquet, booted a water bottle and then proceeded to throw a chair on court. The chair umpire defaulted and Ruud reached the third round.
But their row ignited on social media later following remarks Ruud gave to Scandinavian media months on from that episode in Rome.
'He can say as much as he wants about getting disqualified but it still says 1-0 to me,' Ruud told Tennisportalen.
'I don't know, he was totally crazy when I played him. It was nice to win. If I celebrated after the match or not? I don't care. I was happy I got 90 points and $50,000 in prize money so why wouldn't I celebrate?
'It's his problem that he's an idiot on court.'
Back fired Kyrgios, claiming that Ruud would never have dared label him an 'idiot' to his face in the players' locker room.
'Hey Casper Ruud,' Kyrgios tweeted, 'next time you have something to say, I would appreciate you say it to my face, I'm sure you wouldn't run your mouth so much after that. Until then I will continue to rather watch paint dry then watch you play tennis, boring af.'
He wasn't done.
'I also understand why you have to keep my name in your mouth, because people don't even realise that you play tennis, goodluck in Milan champ.'
Kyrgios, comfortably, won their most recent meeting in Indian Wells - their only clash on a hard court - and Ruud, a beaten French Open finalist this year, will know the task is rarely greater than a dialled in Kyrgios, not least with his monster serve.
It is something John McEnroe believes is the best in the history of the sport. High praise indeed.
'First of all, I've said this before, the guy has got one of the greatest serves in the history of tennis,' McEnroe said after the Medvedev win.
'The guy was serving at 70 per cent - I don't think people realise that's the highest on tour, how big he serves, how good his second serve is – now he is backing it up big time. If he plays like he did last night, he is going to win the tournament.
'The guy is a genius on the court, he doesn't need a coach, he did an unbelievable job tactically. Nick needs to be comfortable with the team that is around him. It's a tough job sometimes being in Kyrgios' box – he's in such a great place mentally and it's like 'he's figured it out'.
