Maria Sharapova has announced she failed a drug test at the Australian Open in January.

“I take great responsibility and professionalism in my career every day. I made a huge mistake,” she told the press. “I let my fans down. I let my sport down.”

Doctors prescribed her meldonium ten years ago for numerous health issues. She said “she had been getting the flu every couple of months, had irregular EKGs, and had evidence of diabetes, which runs in her family.”

The World Anti-Doping Agency (WADA) added it to the list of banned substances on January 1.

Sharapova received a letter from the International Tennis Foundation (ITF) seven days ago about her violation. It did not tell her the penalty she could potentially receive.

They could suspend her for a year.

She also admitted she did not look at the new list of banned substances.

Sharapova has won five Grand Slam titles. The WTA has her ranked seven, but she has only played in one tournament this year. She recently withdrew from the BNP Paribas Open at Indian Wells due to a left forearm injury.