Juan Martin del Potro's return to the US Open final is a celebration of friendship that saw the 2009 champion through his darkest days of injury and doubt.

A dozen friends from del Potro's hometown of Tandil have gained fame in Flushing Meadows, their serenade of "Ole, ole, ole -- Del-Po, Del-Po" an infectious accompaniment to his every match. Despite Del Potro's affectionate post-match teasing, they're more than a boozy bunch of boyhood friends. They're the people who helped him through when it seemed recurring wrist injuries would end his career. The nadir came in 2015, when multiple surgeries had failed to produce a solution.