Sinner’s decision not only affects his singles prep but also costs him and Siniakova a shot at the $1 million prize.

The two young champions, who met as teen-agers, are expected to face off at this year’s U.S. Open. A new book by Giri Nathan ...

Jannik Sinner has withdrawn from the U.S. Open mixed doubles event, where he was going to partner Katerina Siniakova, a day after illness ...