Maria Sharapova's tennis career and Olympic hopes are in jeopardy, and she claims it's all because she failed to click on a link in an email that would have told her to stop taking meldonium.

The five-time major champion says she failed a doping test at the Australian Open in January for the little-known drug, which became a banned substance under the WADA code this year. The former world No. 1 took full responsibility for her mistake when she made the announcement at a news conference Monday in Los Angeles.

Sharapova could face a lengthy ban from the International Tennis Federation, possibly ending her season and preventing her from competing for Russia at the Rio Olympics.

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

The 28-year-old Sharapova received notice last week that she tested positive for meldonium, a blood flow-promoting drug she has been taking for 10 years for numerous health issues. Meldonium was banned because it aids oxygen uptake and endurance, and several athletes across international sports have already been caught using it.