Ashleigh Barty will have her work cut out securing the US Open top seeding and regaining the World No.1 ranking after copping a rugged draw for this week's WTA Tour event in Cincinnati.
Australia's French Open champion must reach at least the semi-finals to regain the No.1 ranking and also clinch top seeding status for the final grand slam of the year getting underway on August 26 in New York.
But the draw has handed Barty few favours.
After a first-round bye, the world No.2 will open her campaign against five-time major champion Maria Sharapova or Wimbledon slayer Alison Riske, the American who snapped Barty's 15-match winning streak in the fourth round at the All England Club.
Should she win her opener, Barty could face former world No.1 Angelique Kerber in the third round and dual Wimbledon champion Petra Kvitova in the quarter-finals.
Osaka will start against either a qualifier or Belarusian Aliaksandra Sasnovich and could run into Serena Williams in the quarters.
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Three Aussies in Cincinnati draw
Nick Kyrgios is among three Australians in the men's main draw in Cincinnati.
Kyrgios faces Italian Lorenzo Sonego in his opener, while Alex de Minaur and Jordan Thompson could clash in round two.
De Minaur also plays an Italian, 2018 French Open semi-finalist Marco Cecchinato, while Thompson has drawn a qualifier.
Alexei Popyrin was unable to join Kyrgios, de Minaur and Thompson in the main draw after American Denis Kudla beat him 6-3 4-6 6-3 in the final round of qualifying.