Four female stars not participating this year

Spain's Garbine Muguruza, last year’s winner

The great Roger Federer, who has been away from tennis

Australian Open and US Open in 2016

Former women's singles World No. 1 

Angelique Kerber will miss US Open 

Vondrousova's withdrawal is a big setback to her fans. 

The US Open an enthralling Grand Slam