LOS ANGELES, United States (AFP) — Sha’Carri Richardson will play no part in the Olympics after being left out of the United States’ 4x100m relay squad, USA Track and Field (USATF) confirmed yesterday.

Richardson had been ruled out of competing in the individual 100m in Tokyo after receiving a 30-day ban for testing positive for marijuana following her victory at the US trials last month.

But the prospect of competing as a member of the relay team had been left open with Richardson’s suspension ending before the opening rounds of the discipline get under way in Tokyo.

USATF rules allowed for the 21-year-old to be selected as one of two coach’s picks alongside the top four finishers from the women’s 100m final at the US trials.

However that door was slammed shut by USATF yesterday after 2016 Olympic 4x100m relay gold medallist English Gardner and Aleia Hobbs were named as the two discretionary picks to complete the six-strong relay pool.

In a statement, USATF expressed sympathy for Richardson’s case but said it had a responsibility to “maintain fairness” for all athletes.

“First and foremost, we are incredibly sympathetic toward Sha’Carri Richardson’s extenuating circumstances and strongly applaud her accountability — and will offer her our continued support both on and off the track,” USATF said.

“While USATF fully agrees that the merit of the World Anti-Doping Agency rules related to THC (marijuana) should be re-evaluated, it would be detrimental to the integrity of the US Olympic Team Trials for Track & Field if USATF amended its policies following competition, only weeks before the Olympic Games,” it added.

“All USATF athletes are equally aware of and must adhere to the current anti-doping code, and our credibility as the national governing body would be lost if rules were only enforced under certain circumstances.”

Newspaper USA Today reported Gardner and Hobbs were told of their selection in the US team before Richardson accepted a reduced one-month suspension for her doping case.

That meant that adding Richardson to the squad with one of the discretionary places would have required either Gardner or Hobbs to be bumped from the team.