World No. 1 talks key to body control.
Serena offers powerful encouragement to Coco Gauff.
The Dane has been struggling to get healthy for a month, but looked good in her win on Friday at Miami.
Christophe Jean claims to have a contract with the father of Naomi Osaka and is seeking big money.
Naomi Osaka on key to clicking with her new coach.
The 16-year-old defeated Naomi Osaka's older sister Mari on Thursday in Miami.
Three-time Miami champion on how family values shaped her.
