Jack Sock has withdrawn from Atlanta with an ankle injury.
The world No. 14 would have been the second seed at the ATP 250. Sock attributed the withdrawal "to an injury I sustained in practice leading up to the tournament."
It was going to be his first appearance since winning the men's doubles title at Wimbledon, which he suggested could help improve his lackluster singles season.
The withdrawal includes both singles and doubles. Mike Bryan will instead play with Frances Tiafoe.
Strokes of Genius is a world-class documentary capturing the historic 13-year rivalry between tennis icons Roger Federer and Rafael Nadal. It is timed for release as the anticipation crests with Roger as returning champion, 10 years after their famed 2008 Wimbledon championship – an epic match so close and so reflective of their competitive balance that, in the end, the true winner was the sport itself.