One of the most odd failed drug tests in recent memory occurred back in January and came to light today. Tennis superstar Maria Sharapova revealed during a press conference yesterday that she had failed a drug test during the Australian Open.

"I take great responsibility and professionalism in my career every day," Sharapova said. "I made a huge mistake. I let my fans down. I let my sport down."

The 28-year-old, was believed to have called the press conference to announce her retirement, instead she described her medication situation over the past 10 years. Over the last decade, Sharapova had been prescribed the drug mildronate, or meldonium. Meldonium is a blood flow-promoting drug banned because it aids oxygen uptake and endurance, while helping out a number of health issues including low magnesium levels.

On January 1st, the drug meldonium had been placed on the banned list by WADA. Unknown to her, Sharapova continued the drug, eventually leading to her failed test. The penalty for knowingly taking a banned substance can be upward of 4 years, but if done unintentionally the max is 2 years. In Sharapova's case, mitigating circumstances could allow her to be given very few sanctions if any at all.

"I know with this that I face consequences," Sharapova said. "I don't want to end my career this way, and I really hope I'm given another chance to play this game."