Sprinter Sha'Carri Richardson, who was poised to be one of the faces of Team USA in Tokyo, could miss the Olympics after testing positive for marijuana.

Driving the news: Richardson, 21, won the 100 meters at the U.S. track & field trials two weeks ago, but her positive test invalidates her result.

• She has accepted a 30-day suspension under the anti-doping rules of World Athletics, which will begin from the time her test was taken on June 28.
• Richardson could return in time to race in the 4x100-meter relay in Tokyo on Aug. 6. The decision would be up to USA Track & Field.

Why it matters: The Texan, who is the second-fastest woman in the 100 meters this year (10.72 seconds), was aiming to become the first American woman to win gold in the event since Gail Devers in 1996.

What she's saying: "I know what I did, I know what I'm supposed to do, what I'm allowed not to do, and I still made that decision," Richardson said in an interview with NBC's "Today Show" on Friday morning.

• Richardson said that she had been dealing with her mother's death, as well as the pressure of participating in the trials, which led her to a state of "emotional panic."
• "Don't judge me, because I am human ... I just happen to run a little faster," she added.

Of note: Adult recreational use of marijuana is legal in 18 states and the District of Columbia. That includes Oregon, which is where Richardson tested positive.

• The four major U.S. sports leagues have softened their stances in recent years, reducing restrictions and punishments.
• The World Anti-Doping Agency classifies cannabis as a "Substance of Abuse," and it currently carries a four-year ban — unless an athlete can prove that their ingestion of the substance was unrelated to sports performance.

Go deeper:Major sports leagues are easing up on marijuana