NEW YORK (AP) — Jannik Sinner pulled out of theU.S. Openmixed doubles tournament shortly before it began on Tuesday, a day after he quit in the first set of theCincinnati Openfinal because he was feeling ill. The No. 1-ranked Sinner, the defending champion in singles at Flushing Meadows, was supposed to compete inmixed doubleswith Katerina Siniakova. Sinner and Siniakova will be replaced by Americans Danielle Collins and Christian Harrison. Collins and Harrison received entry because they had the highest singles and doubles rankings combined among the teams on the alternate list. Collins is ranked 59th in singles, and Harrison is ranked 17th in doubles. They were set to play Belinda Bencic and Alexander Zverev in a first-round match later Tuesday. The U.S. Tennis Association announced the withdrawal and replacement less than an hour before the first contests were scheduled to be played in the new mixed doubles event. ___ AP tennis:https://apnews.com/hub/tennis