Jannik Sinner is teaming up with Katerina Siniakova for the U.S. Open Mixed Doubles after Emma Navarro opted out. With Navarro focusing on the WTA 500 in Monterrey, Sinner's partnership with Siniakova, a 10-time Grand Slam doubles champ, is generating excitement. Sinner's quick transition from facing Carlos Alcaraz in Cincinnati to New York highlights his relentless drive. Can this new duo challenge the likes of Zverev and Bencic? #SinnerSiniakova #USOpen #TennisRivalry #Sports #Tennis #SinnerSiniakova