When Maria Sharapova called for a press conference on Monday, stating that she had a “major announcement” to make, many thought that she might be about to join Peyton Manning as a champion who chose to leave their game. However, she would throw an unexpected curveball.

The veteran announced that she had failed a drug test during the Australian Open in January. That result came to her attention on March 2. Specifically, Sharapova tested positive for the drug meldonium (also known as mildronate), a drug she said that she had been prescribed since 2006. It is also a drug that made it onto the ban list for 2016 after one year of being on the watch list and many years of being a legal substance.

Sharapova explained, “I was getting sick very often, I had irregular EKG results, and I had a family history of diabetes.” For these reasons, along with the fact that she had a deficiency in magnesium, a family physician prescribed the drug.

The 28-year-old made no excuses, saying “I take full responsibility for it.” She would admit, “I received a letter on Dec. 22 from WADA, an email with changes happening for next year as well as reporting your whereabouts, and a link to a button where you can press to see the prohibited items for 2016. I did not look at that list.”

Sharapova was forthcoming, stating “I thought it was very important for me to come out and speak about this in front of all of you because throughout my long career, I have been very open and honest about many things,” she said. “I made a huge mistake, and I’ve let my fans down. I’ve let this sport down that I have been playing since the age of four and that I love so deeply.”

The Russian acknowledged that she expected repercussions, the extent of which is yet to be determined. (Nike, one of her main sponsors, announced later in the day that they are suspending their relationship with her.) However, Sharapova would find a way to insert some humor during the difficult admission. “I know many of you thought that I would be retiring today,” she said. “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.”