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London (CNN) Maria Sharapova's 15-month suspension for failing a drug test is likely to extend her career all the way to the Tokyo Olympics in 2020, according to the Russian's longtime agent Max Eisenbud.

The five-time major winner rocked the tennis world a year ago when she announced she had tested positive for meldonium, an over-the-counter heart medication commonly used in the countries formerly comprising the Soviet Union.

Sharapova said she hadn't realized the drug -- which she had taken for more than a decade for various health issues -- had been put on the 2016 prohibited list.

She is scheduled to return to the women's tour on April 26 at an event in Stuttgart, Germany after organizers gave her a wildcard.

"If (the suspension) didn't happen, this probably would have been her last year," IMG's Eisenbud told CNN in a phone interview. "I think she'll play through Tokyo" if healthy.

Photos: Maria Sharapova: Richest female athlete of past decade Photos: Maria Sharapova: Richest female athlete of past decade Sharapova, age 14, plays her first professional tournament in March 2002. She defeated Brie Rippner at the Pacific Life Open in Indian Wells, California. Hide Caption 1 of 11 Photos: Maria Sharapova: Richest female athlete of past decade Sharapova holds up her trophy after she won Wimbledon in July 2004. The 17-year-old defeated Serena Williams in the final for her first Grand Slam title. Hide Caption 2 of 11 Photos: Maria Sharapova: Richest female athlete of past decade Sharapova serves during the 2006 U.S. Open semifinals. She advanced to beat Justine Henin in the final. It was her second Grand Slam title. Hide Caption 3 of 11 Photos: Maria Sharapova: Richest female athlete of past decade Sharapova is given a painting from the Children of Chernobyl Foundation in July 2007. That year, she became a U.N. global ambassador focused on the Chernobyl Recovery and Development Program. Hide Caption 4 of 11 Photos: Maria Sharapova: Richest female athlete of past decade Sharapova won her third major title at the 2008 Australian Open. Hide Caption 5 of 11 Photos: Maria Sharapova: Richest female athlete of past decade Off the court, Sharapova has become a fashion icon and a popular spokeswoman for many major companies. Her endorsements have included Nike, Gatorade, Canon and Cole Haan. Hide Caption 6 of 11 Photos: Maria Sharapova: Richest female athlete of past decade Sharapova falls to her knees after winning the 2012 French Open to complete the career Grand Slam. She also won the French Open in 2014. Hide Caption 7 of 11 Photos: Maria Sharapova: Richest female athlete of past decade Sharapova, left, at the London 2012 Olympic medal ceremony at Wimbledon with Serena Williams, center, and Victoria Azarenka. Sharapova finished with the silver after losing to Williams in the final. Hide Caption 8 of 11 Photos: Maria Sharapova: Richest female athlete of past decade Sharapova carries the Olympic torch in Sochi, Russia, during the opening ceremony for the 2014 Winter Olympics. Hide Caption 9 of 11 Photos: Maria Sharapova: Richest female athlete of past decade A shopper in Shanghai, China, walks past a Nike advertisement featuring Sharapova. Hide Caption 10 of 11 Photos: Maria Sharapova: Richest female athlete of past decade Sharapova signs autographs after winning a match at last year's Australian Open. She later announced she had tested positive for banned drug meldonium and was banned for two years, later reduced to 15 months. Hide Caption 11 of 11

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