Sharapova had struggled with chronic shoulder problems for some time, and the five-time Grand Slam champion and former world number one had slipped to 373rd in the rankings.
The then 32-year-old said it would be too painful to walk away, writing: “How do you leave behind the only life you’ve ever known?
“How do you walk away from the courts you’ve trained on since you were a child, the game you love, one that brought you untold tears and unspeakable joy, a sport in which you found a family, along with raving fans? behind you for more than 28 years?
“I’m new to this, so please forgive me. Tennis: I say goodbye.
Having heralded her talent by winning Wimbledon at the age of just 17 in 2004, Sharapova established herself as one of the greats of her day: among her contemporaries, only Serena and Venus Williams have won more slam singles titles.
Sharapova added the US Open title in 2006 and the Australian Open in 2008 before lifting the trophy twice at Roland Garros, in 2012 and 2014. She is one of 10 women to win a career Grand Slam.
Her impact on the court was surpassed by her profile off it, with the Russian being the highest-earning female athlete in the world for much of her career.
In 2016 came the bombshell announcement that he had failed a doping test for the heart drug meldonium, which had been added to the banned list earlier that year.
Sharapova was banned for two years, reduced to 15 months on appeal.
She returned to action in April 2017, but was unable to reach her previous heights, peaking at 21 in the rankings and reaching just one more Grand Slam quarterfinal.
In July of last year, Sharapova became a mother with the birth of her son Theodore.