American champion Sha'Carri Richardson cannot run in the Olympics after testing positive for THC.
Richardson, who won the 100 at Olympic trials in 10.86 seconds tested positive at the Olympic trials and so her result is erased.
Fourth-place finisher Jenna Prandini is expected to get Richardson's spot in the 100.
Richardson accepted a 30-day suspension that ends July 27, which would be in time to run in the women's relays.
Richardson was expected to face Jamaica's Shelly-Ann Fraser-Pryce in one of the most highly anticipated races of the Olympics.
Richardson had what could have been a three-month sanction reduced to one month because she participated in a counseling program. There have been wide-ranging debates about whether marijuana should be considered a performance-enhancing drug, the U.S. Anti-Doping Agency makes clearon its website that “all synthetic and naturally occurring cannabinoids are prohibited in-competition, except for cannabidiol (CBD),” a byproduct that is being explored for possible medical benefits.