Ruud probably suffered from gastroenteritis against Zverev
Like Aryna Sabalenka in the women's singles quarter-finals, Casper Ruud was probably suffering from gastroenteritis against Alexander Zverev in the men's singles semi-finals. In the 3rd and 4th sets, the Norwegian was moving much less well than his standards, and he didn't shake hands with either his opponent or the chair umpire at the end of the match, so as not to risk contaminating them.
Zverev confirmed in his post-match interview that he felt Ruud was much less mobile than usual after two top-level opening sets.
Alexander Zverev: "The first two sets were at a very high level. Then, at the end of the 3rd set, I saw that he wasn't moving as well as he had at the start and that he wasn't feeling well. But his shots were still as good as ever, and it was mainly in his movement that you could see things weren't going well. But if I'd been too passive, he could have won.
All credit to him for fighting right to the end. He's a great person and a great champion."