The United States mixed 4x400m relay team was reinstated early Saturday in Japan after being disqualified Friday during the event's Olympic-debut prelims in Tokyo, at the time eliminating a possible chance for nine-time Games medalist Allyson Felix to earn a 10th in Saturday's final.

An exchange between first and second legs Elija Godwin and Lynna Irby, each sixth in the open 400m at U.S. Olympic Trials, was found to have taken place outside the passing zone.

"For all takeovers, athletes are not permitted to begin running outside their takeover zones, and shall start within the zone," World Athletics Technical Rules 24.19 states. "If an athlete does not follow this Rule, their team shall be disqualified."

Of the seven second-leg athletes awaiting the first baton pass, part of a three-turn stagger that breaks following the exchange, Irby in lane three was the only one positioned at the back end of her zone with just meters to spare, perhaps lined up at the wrong marker.

But less than four hours later, the disqualification was reversed. In a tweet, U.S. Track and Field said the team had been reinstated and would compete in Saturday's final.

While it still remains uncertain whether Felix will even run in the final, the legendary sprinter was the second leg on Team USA's 2019 world-championship winning final team, her 12th world title. She did not compete in the Tokyo prelims, but teams can switch up members between rounds, allowing for more than four to take home medals.

Regardless, Felix has two other chances in the open 400m and women's 4x400m relay. If she were to secure a medal it would be her 10th at the Games, tying Carl Lewis for most Olympic track and field medals by an American, and also break her tie with Jamaica's Merlene Ottey for most Olympic track and field medals by a woman.

Taylor Manson and Bryce Deadmon were the third and anchor legs on the first-round U.S. team.

Relays have been a thorn in the side of the U.S. over the last couple of decades, particularly in the 4x100m and rarely over four laps.

The Dominican Republic was also disqualified, but on different terms; officials ruled that one of its athletes didn't maintain order while awaiting the baton in the exchange zone.