A war of words between the two parties have broken out.
The loss is the latest setback for Osaka as she fights to maintain her position at the top of the rankings.
Five players and one position - here are the different scenarios Osaka and her rivals are facing in Miami.
Trouble is brewing off the court for the Australian Open champion.
Belinda Bencic came up with some breathtaking tennis to knock out defending champion Naomi Osaka in Indian Wells.
Naomi Osaka maintained her chance of a second consecutive title in Indian Wells with a comprehensive straight-sets win over Danielle Collins.
The Australian Open champion reflects on her surge in popularity following her latest win.
"It's not about defending, it's about getting another one."
Can the 21-year-old Japanese player hold on to top spot over the next two weeks?
The Australian Open champion has confirmed her replacement for Sascha Bajin.
The two grand slam champions have given their insight about the world No.1 following her recent loss.
Osaka is currently one of the most sought after tennis players in the world, but not everything is perfect.
The Australian Open champion reflected on his previous struggles as Naomi Osaka also got recognised for her achievements in sport.
The world No.1 made the surprise announcement on social media
The world No.1 has become the latest player to withdraw from the Premier event in Qatar.
The women's final attracted some impressive TV figures.
At the age of 21 Osaka has managed to achieve something that no other tennis player from her continent has.
Charleston Post and Courier columnist James Beck reflects on Naomi Osaka's Historic win at the Australian Open!
Stuart Fraser from The Times chats with Ubitennis about Naomi Osaka's triumph in Melbourne Park.
After failing to convert three consecutive match points in the second set. the 21-year-old has become the first Japanese player to win the Melbourne title.