US Open: Novak Djokovic's fading body is now handing out diminishing returns

Novak Djokovic lost to Mariano Navone in the US Open first round on Monday. The scoreline ended 7-6 (7-5), 5-7, 4-6, 6-2, 6-1. Djokovic struggled with his fitness throughout the match, often appearing in pain. He said, "Oftentimes I feel like I am imprisoning myself," regarding his constant drive for perfection.