|Serena Williams, shown in March, will try to achieve|
the first calendar-year Grand Slam since Steffi Graf
in 1988. Photo by Paul Bauman
Garbine Muguruza (9) -- This year's Wimbledon runner-up withdrew from Stanford with abdominal strain, then lost early in Toronto and Cincinnati. NorCal connection: Won doubles title in 2014 Bank of the West Classic with fellow Spaniard Carla Suarez Navarro.
|Novak Djokovic, also shown in March, seeks|
his first U.S. Open title in four years.
Photo by Paul Bauman