Heading into the final major of the year Federer, Nadal, and Djokovic are all tied at 20 majors a piece. But they are also struggling with injuries. Federer and Nadal are at least out until the end of the season. While Djokovic is trying to win the elusive calendar slam. How have their long seasons and past matches impacted their physical bodies? Mileage is definitely a factor for the Big 3. We may never see all three players fully healthy on the tour again. Has the golden age of men’s tennis finally come to a close? Who will win the US Open? Djokovic or a young gun such as Zverev, the singles gold medalist.