American sprinter Sha'Carri Richardson has reportedly failed a drug test and this could mean that she would be missing the Tokyo Olympics 2020.

Sha'Carri Richardson was expected to contend for a gold medal. However, she tested positive for what is classified as a substance of abuse, CBS Sports reported.

A positive test result would disqualify her U.S. Olympics Trials performance. In addition, she could also be suspended from competition by the World Anti-Doping Agency.

The American sprinter did not use steroids but is facing a 30-day suspension for testing positive for marijuana.

Jenna Prandini will replace Sha'Carri Richardson in the 100 meters if she is disqualified or suspended. Prandini finished fourth in the 100 meters at the U.S. Olympics Trials.

One source familiar with the matter said the positive test came at the U.S. Olympics Trials last month when Richardson finished by being a gold medal contender, winning the 100 meters in 10.86 seconds, The Guardian reported.

Prandini was already approached to run for the U.S. in Tokyo Olympics 2020, according to reports. Sha'Carri Richardson earlier posted a tweet that says, "I am human."

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Sha'Carri Richardson's Positive Drug Test

The 21-year-old American sprinter was set to appear on NBC's Today Show on Friday. She was billed to run in the 200 meters at the Stockholm Diamond League meeting in Sweden this coming weekend. However, she was not on the entry list for the race.

The World Anti-Doping Agency had banned cannabis. However, if athletes can prove that their ingestion of the substance was unrelated to sports performance, their suspension would be three months compared to the usual four years given.

The ban can be reduced to one month if an athlete is willing to undertake an approved treatment program in collaboration with their national anti-doping body.

Sha'Carri Richardson had revealed that her biological mother has passed away in the days before the Olympic Trials.

After the 100 meters sprint in Eugene, the American sprinter said that her family had kept her grounded, adding that she is grateful for them. Richardson further noted that without her family, "there would be no me," Australian News reported.

The American sprinter could also appeal any sanction to the Court of Arbitration for Sports and any other sports body who felt the punishment was too lenient.

Cannabis Prohibited

The drug is only banned on the day before the competition and ending at its conclusion. Athletes may have up to 150 nanograms per milliliter of THC without causing a positive test, The New York Times reported. THC is the primary psychoactive substance in marijuana.

The United States Anti-Doping Agency (USADA) considered marijuana a prohibited substance as it is identified as both performance-enhancing and a drug of abuse.

Last month, the USADA suspended Kahmari Montgomery for a month after he tested positive for marijuana. Montgomery is a middle-distance runner.

Sha'Carri Richardson's agent, Renaldo Nehemiah, has yet to comment on the athlete's positive drug test.

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