NEW YORK -- For years now, there has been a lot of hand-wringing over the specter of a post-Williams sisters landscape in American tennis.
Venus and Serena Williams, at 36 and 34, are the oldest women in the draw and, presumably, they will graduate from the sport sooner rather than later.
Friday at the US Open -- with the sisters both enjoying a day off -- offered a glimpse of what that future might look like. Frankly, it might not be completely awful.
In a span of less than 15 minutes, 23-year-old Jack Sock took down 2014 US Open champion Marin Cilic in straight sets, and 21-year-old Madison Keys overcame a 5-1 third-set deficit to defeat Naomi Osaka.