They are two of undoubtedly the most recognised and successful players in tennis history, who are more used to facing each other across a net rather than in the press.
Recent events, however, have brought the two rivals head-to-head again, as Maria Sharapova recently published her memoir Unstoppable, where she makes several references aimed at her long-time rival Serena Williams, and it seems she has gotten a reaction out of 23 time singles Grand Slam winner.
A body image argument has been sparked between the two after the Russian commented on Williams' 'thick arms and legs', and Williams has issued a subtle response through social media.
The American, who has missed most of the tennis calendar so far this year to give birth to her daughter Alexis Olympia Ohanian Jr, used her husband's platform Reddit to pay tribute to her girl and her own mother.
Williams said: "Dear Mom, You are one of the strongest women I know. I was looking at my daughter (OMG, yes, I have a daughter) and she has my arms and legs! My exact same strong, muscular, powerful, sensational arms and body.
"I don’t know how I would react if she has to go through what I’ve gone through since I was a 15 year old and even to this day…."
She even went as far as to take a swipe at Sharapova for the drugs ban she received, which has blighted the former Wimbledon champion's career.
"I’ve been called man because I appeared outwardly strong," she wrote.
"It has been said that that I use drugs (No, I have always had far too much integrity to behave dishonestly in order to gain an advantage)."
Williams may be taking time away from the court to spend it with her family, but clearly she has lost none of the competitive edge that she has honed with years on the court.
When her eventual return happens, a potential face off with rival Sharapova may have just been given some extra spice with their current war of words.