Maria Sharapova's tennis career will resume sooner than expected, reports CNN.

The five-time grand slam champion has had her two-year drugs ban reduced to 15 months by the Court of Arbitration for Sport (CAS) meaning she will be back in time for the French Open in May 2017.

Sharapova tested positive for banned substance meldonium at the Australian Open in January and was subsequently banned for two years by the International Tennis Federation (ITF).

But CAS has shaved nine months off that original verdict, meaning Sharapova is eligible to compete again on April 25.

The sport was plunged into shock when Sharapova announced at a Los Angeles press conference in March she had failed a drugs test. A provisional ban was announced by the ITF shortly after.

Sharapova said she was first prescribed meldonium, also known as mildronate, in 2006 for heart issues and was unaware it had been added to the banned substance list by the World Anti-Doping Agency (WADA) as of January 1.

She acknowledged taking it before each match she played at the Australian Open as she was knocked out of the tournament at the quarterfinal stage by her nemesis Serena Williams.

The former world No. 1 claimed she had been taking meldonium since 2006 for heart issues, a magnesium deficiency and because her family has a history of diabetes.

Meldonium was added to the prohibited list "because of evidence of its use by athletes with the intention of enhancing performance," WADA said on its website.

Sharapova said she simply failed to read an email that stated meldonium would be added to the banned list on January 1 this year. In evidence heard during the tribunal it was stated her IMG agent Max Eisenbud also failed to check.