Jannik Sinner has returned to the training court. He withdrew from the US Open before it started. A knee injury meant he missed playing in New York entirely. Three weeks of treatment are behind him. He is still working through rehab. China is his comeback destination. He wants to join the Asian circuit. The US Open served as the season's final Grand Slam. Alexander Zverev beat Ben Shelton in the championship match. That earned Zverev his second Grand Slam title of the year.