At the 2016 Australian Open, Sharapova tested positive for meldonium, which had been classified as a banned substance a few weeks earlier.
Ignorance of the new Wada rules was no excuse and she ended up serving a 15-month drugs ban.
She said in a statement at the time: “I received a letter from the ITF that I failed a drugs test at the Australian Open. I take full responsibility for it.
“For the past 10 years I have been given a medicine called mildronate by my family doctor and a few days ago after I received the ITF letter I found out that it also has another name of meldonium which I did not know.
“It is very important for you to understand that for 10 years this medicine was not on Wada’s banned list and I had legally been taking the medicine for the past 10 years.
“But on January 1st the rules had changed and meldonium became a prohibited substance which I had not known.”
“I was given this medicine by my doctor for several health issues that I was having in 2006,” Sharapova continued.
“Throughout my long career I have been very open and honest about many things and I take great responsibility and professionalism in my job every single day and I made a huge mistake.
“I let my fans down. I let the sport down I have been playing since the age of four and I love so deeply.
“I know with this I face consequences and I don’t want to end my career this way and I really hope I will be given another chance to play this game.
“I know many of you thought I was retiring but if I was ever going to announce my retirement it would probably not be in a downtown Los Angeles hotel with this fairly ugly carpet.”