Which is why it's probably no surprise that Williams took a subtle dig at her rival on Twitter before her 6-1 6-3 defeat to Angelique Kerber in the third round at the Australian Open.
A Williams supporter posted on Twitter that she was hoping Sharapova would beat Kerber.
The American oddly replied to the tweet with an emoji of a blank facial expression.
Be mad at me later… I kinda want sharapova to win tomorrow ? pic.twitter.com/B6RoOdN416
— RenasArmy (@RenasArmy) 19 січня 2018 р.
The 36-year-old was forced to pull out of the Australian Open after having reservations over her fitness levels after giving birth to her daughter in September.
Williams, a 23-time major winner, is expected to make her return to the sport by the time the French Open rolls around.
Things might get interesting if she happens to bump into Sharapova at Roland Garros.