UFC 249 is going ahead with Justin Gaethje stepping in for lightweight champion Khabib Nurmagomedov against Tony Ferguson for the interim 155-pound title.

UFC president Dana White tweeted the news Monday, saying the April 18 matchup is signed and will take place "somewhere on EARTH!!!!"

The unbeaten Nurmagomedov, back home in Russia, said he wouldn't break quarantine even if he was to able to get past COVID-19 travel restrictions.

The UFC was been forced to postpone cards originally slated for March 21 in London, March 28 in Columbus, Ohio, and April 11 in Portland. The UFC initially planned to shift them to the UFC Apex facility in Las Vegas behind closed doors due to local authorities' restrictions on crowds.

But it was forced to look elsewhere after the Nevada State Athletic Commission voted to suspend all combat sports events in the state.

White's quest hit another obstacle later Monday when the Association of Ringside Physicians issued a statement calling for the indefinite suspension of all combat sports events.

“Any combat sport taking place during this global pandemic places the athletes, officials, and anyone else involved in the event under unnecessary risk of infection and transmission of COVID-19,” ARP's statement read. “In addition, combat sports athletes often require medical attention after a bout, and we do not wish to see any additional strain on an already overwhelmed medical system.”

The mixed martial arts promotion last held a Fight Night card March 14 in Brazil but without spectators.

White has insisted UFC 249 with its marquee main event, originally slated for Brookyln, will go ahead despite other sports shutting down due to the pandemic.

The 31-year-old Gaethje (21-2-0) is an all-action, hard-punching fighter coming off first-round wins over Donald (Cowboy) Cerrone, Edson Barboza and James (The Texecutioner) Vick.

The 36-year-old Ferguson (25-3-0) has won his last 12 fights dating back to 2013.

Nurmagomedov (28-0-0) left California to return home when the UFC had tentative plans to stage UFC 249 in the United Arab Emirates.

Nurmagomedov and Ferguson have been officially booked to fight five times since December 2015.

The first scheduled bout was called off in late 2015 due to an undisclosed injury for Nurmagomedov. A second proposed matchup in April 2016 was scrapped when Ferguson had a problem with his lungs. The fight was booked for a third time at UFC 209 in March 2017, but was called off on the day of the weigh-in when Nurmagomedov became seriously ill from his weight cut.

The UFC scheduled the bout for the fourth time for UFC 223 in April 2018. Six days before the fight, Ferguson tore a ligament in his knee while walking onto a TV set to promote the fight.

This report by The Canadian Press was first published April 6, 2020.