Shingo Kunieda was fretting. It was Thursday, and Kunieda, his coach, his trainer, his clothing sponsor and his wife were all bent over, trying to pump air into the tires of his wheelchair.

In an hour, Kunieda, one of the most accomplished men’s wheelchair tennis players in the world, would be contesting the first wheelchair match at Arthur Ashe Stadium, and something was not right.

Nearby, Mike Zangari was operating a portable compression machine, one of two that he keeps in the trunk of his car. He had realized that a rubber tube inside the tire of Kunieda’s wheelchair had a slow leak. It would most likely affect his ability to maneuver around the court.