Jannik Sinner has withdrawn from the U.S. Open mixed doubles event, where he was going to partner Katerina Siniakova, a day after illness forced the world number one to retire five games into his Cincinnati Open final.
Sinner, the reigning Australian Open, Wimbledon and U.S. Open champion, looked uncomfortable in sweltering conditions on Monday at Cincinnati where he retired after falling behind 5-0 to Carlos Alcaraz in the first set.
"Yesterday I didn't feel great and I'm really sorry to disappoint you. Thank you so much to everyone supporting me on-site and from home, your support means the world," world number one Sinner posted on X on Tuesday.
"Congrats to @carlosalcaraz and his team, you're having an incredible season and I wish you all the best for what's ahead. Now it's time to rest a couple of days before getting back to work."
The reimagined mixed doubles competition, a two-day event featuring 16 teams, began on Tuesday but the official draw and order of play no longer featured the Sinner-Siniakova entry.
Danielle Collins and Christian Harrison replaced the Sinner-Siniakova partnership in the draw and will play Belinda Bencic and Alexander Zverev in the first round.
The main singles draw at the U.S. Open is scheduled to begin on Sunday.