Osaka, Serena, Barty, Halep among 13 Slam champs in US Open 2019 field
Rosmalen, Netherlands. 13th June, 2019. ROSMALEN, Tennis Libema Open 2019, WTA and ATP tournament, 13-06-2019, Autotron Rosmalen, Robin Haase (NED) Credit: Pro Shots/Alamy Live News Stock Photo - Alamy