Jannik Sinner pulled out of the U.S. Open mixed doubles tournament shortly before it began on Tuesday, a day after he quit in the first set of the Cincinnati Open final because he was feeling ill.

Carlos Alcaraz won the Cincinnati Open title in a little more than 20 minutes on Monday after top-ranked Jannik Sinner was forced to retire because of illness during the first set.

Sinner was going to partner Kateřina Siniaková, probably the greatest active doubles player on earth, in a compelling alliance of the two tennis disciplines.