US Open champ Jannik Sinner is a young man in a hurry. He is 23, is No. 1 and has 2 Slam titles

New U.S. Open champion Jannik Sinner is making big strides in a short amount of time

​New U.S. Open champion Jannik Sinner is making big strides in a short amount of time New U.S. Open champion Jannik Sinner is making big strides in a short amount of time US