For the second time this year, Mikaela Mayer has watched a fight canceled due to the ongoing coronavirus disease (COVID-19) pandemic.

This time around, it had a physical impact.

The unbeaten 130-pound contender was forced to withdraw from a planned June 9 ESPN-televised appearance  after testing positive for COVID-19. Mayer was due to face Helen Joseph—a veteran contender from Connecticut by way of Nigeria—in the chief support of a show headlined by training stablemate Shakur Stevenson, to air live on ESPN from MGM Grand Conference Center Ballroom in Las Vegas (Tuesday, 7:00 p.m. ET/4:00 p.m. PT), but instead is scratched from the card and forced into isolation until she fully recovers.

“I am heartbroken to report that I will no longer be fighting on Tuesday’s Top Rank card due to a positive result in my COVID-19 test yesterday,” a dejected Mayer through her verified social media platforms on Sunday. “It came as a complete surprise. I am currently asymptomatic and am quarantining at an off-site location per recommended guidelines.

“The rest of my team tested negative and they are all in good health.”

The rest of the show will remain intact, including the evening's headliner, as Stevenson (13-0, 7KOs)—a reigning featherweight titlist—faces Puerto Rico's Felix Caraballo (13-1-2, 9KOs) in a non-title fight at junior lightweight.

Mayer—a member of the 2016 U.S. Olympic boxing team and current rising contender—becomes the first pro boxer to test positive for COVID-19 while scheduled to fight. It came as the result of strict testing standards in place, as part of a months-long collaborative effort between Top Rank and the Nevada State Athletic Commission to move forward with live televised boxing in the United States.

"Top Rank has a protocol playbook in place, including extensive measures in case of a positive COVID-19 test," noted the Las Vegas-based company in a statement. "Those policies were followed as planned. We wish Mikaela the best and look forward to seeing her in the ring very soon."

Mayer has now spent nearly all but four weeks in 2020 training for fights that failed to materialize. A planned clash with former featherweight champion Melissa Hernandez this past St. Patrick’s Day in New York City was canceled less than a week before fight night due to the initial wave of the ongoing global health crisis.

Top Rank also had a March 14 show—that was to have been headlined by Stevenson (13-0, 7KOs) in a featherweight title defense versus Miguel Marriaga—canceled as well, along with several others over the course of the spring. The Las Vegas-based company has since worked tirelessly with the Nevada State Athletic Commission to come up with a sufficient protocol in order for boxing to resume in state.

With that came plans to begin its summer series of events, airing live on ESPN platforms. The first show will still go on, though not for Mayer as the 29-year old Los Angeles native—who now lives in Colorado Springs—who has been out of the ring since a 6th round stoppage of Alejandra Soledad Zamora last October.

It’s unclear when her next fight will come, as she is for now left with nothing to show for back-to-back training camps.

“I was really looking forward to bringing back boxing for all of you and I’m disappointed for myself, my team, my supporters and for my opponent, Helen Joseph, who worked just as hard to be here this week and put on a show for everyone.

“After two hard back-to-back camps, not being able to step in to the ring both times, you can imagine how disappointed I am. However, these protocols were put into place for a reason and it's more important to care about the health and well-being of my team and the people at this event. So I am complying with the rules set forth by the Nevada State Athletic Commission and Top Rank to keep everyone safe.”

Internal discussion suggests a clean bill of health should be enough to get her in the ring without having to wait too long on the sidelines.

“Top Rank assures me they want her back in action as a soon as possible,” George Ruiz, Mayer’s career-long manager told “They’re doing all they can to make the best of this unexpected development. She’s totally asymptomatic and she’ll be back soon. She’s going to take every precaution in the meantime to make sure everyone else is too.”

Rookie heavyweight prospect Jared Anderson (3-0, 3KOs) could prove to be the benefactor of the fallout. The 20-year old Toledo native faces Johnny Livingston in an already scheduled televised bout and would seem to be the logical choice to elevate to chief support, although that has yet to be established as this goes to publish.

As for Mayer, another unexpected pause in her career comes of the situation. Ever the optimist, she plans to once again make the most of it.

“I will just have to take a quick break but I will be in the ring soon,” acknowledges Mayer. “I appreciate all the love and support. Please tune in to ESPN on Tuesday night and support the card and all of the fighters. Boxing is back and I'll be back.”

Jake Donovan is a senior writer for Twitter: @JakeNDaBox