Sha’Carri Richardson, an American track and field sprinter, who was set for a star turn at the Tokyo Olympics this month, could miss the Games after testing positive for marijuana, according to The New York Times.

In June, the 21-year-old won the women’s 100-meter race at the U.S. track and field trials in Oregon, but her positive marijuana test automatically invalidated her result.

It is unclear whether Richardson will appeal the test result and the disqualification. It is also unclear how long she will be suspended. It could be as short as one month, according to the news outlet.

Jenna Prandini, 28, who placed fourth at the trials, has been notified that she will now be one of the three American women running the 100 meters in Tokyo.

Richardson could still return to competition just before the Olympics as her one-month ban could be set to begin at the time of her positive test at the trials, which begin on July 23.

A newspaper in Jamaica called The Gleaner first reported the news of Richardson’s positive test.

The athlete has not yet commented on the positive test, but early Thursday afternoon she tweeted, “I am human.”

The U.S.A. Track & Field officials did not immediately respond to requests for comment. The United States Anti-Doping Agency (USADA) and the Athletics Integrity Unit officials have also not responded to requests for comments.

Marijuana is on the list of the World Anti-Doping Agency (WADA) of prohibited substances and USADA and the United States Olympic & Paralympic Committee are signatories to the WADA code.

The USADA says marijuana is a prohibited substance because it can boost performance, it poses a health risk to athletes, and its use violates the spirit of the sport.

The maximum duration of a suspension for testing positive for marijuana can be up to two years, while the minimum is a month if athletes can prove that they did not use marijuana to enhance their performance or if they complete a substance abuse treatment program.

After qualifying for the Olympic team, Richardson told NBC that a week before the trials she learned that her biological mother had died.

She said of her family, “Y’all see me on this track, and y’all see the poker face that I put on, but nobody but them and my coach know what I go through on a day-to-day basis.” The article was published in The New York Times.