The No. 1-ranked Sinner, the defending champion in singles at Flushing Meadows, was supposed to compete in mixed doubles with Katerina Siniakova.

The scheduling of the Cincinnati Open final on Monday has caused chaos ahead of the start of the new-look US Open mixed doubles event

World No. 1 Jannik Sinner is officially out of the U.S. Open Mixed Doubles tournament after falling ill in Cincinnati. The Italian retired down 5-0 against Carlos Alcaraz in the Cincinnati Open final on Monday and was due to play Mixed Doubles Tuesday with partner Kateřina Siniaková in New York.

Sinner had to forfeit his Cincinnati Open singles final against Carlos Alcaraz after five games due to illness.

Jannik Sinner has a new partner for the U.S. Open mixed doubles tournament, where Emma Raducanu and Carlos Alcaraz will face the No. 1-seeded team in the first round.