One day after the headline bout at UFC 251 in Abu Dhabi was called off, negotiations are reportedly under way for one of the biggest fights of the year to take its place at the Fight Island opener. It was confirmed on Saturday that <a href="https://www.thenational.ae/sport/other-sport/ufc-251-gilbert-burns-ruled-out-of-fight-island-after-testing-positive-for-coronavirus-reports-1.1043778">Gilbert Burns had tested positive</a> for Covid-19 before boarding a plane for the UAE, ruling the Brazilian out of his welterweight title clash against champion Kamaru Usman on July 12. However, multiple reports in the United States claim the UFC are attempting to book Jorge Masvidal to step into the breach and face Usman instead, with ESPN initially reporting discussions had taken place. Footage emerged early Sunday of Masvidal taking and passing a coronavirus antibody test, while ESPN reported his management saying the American was “absolutely willing” to go up against Usman. Usman has since posted a tweet teasing a possible tussle. Still, given the stringent Covid-19 protocols in place for Fight Island, there remain a number of significant hurdles to overcome. All competitors must pass three Covid-19 tests from arrival in Abu Dhabi up until they fight, with a period of quarantine mandatory at the W - Abu Dhabi hotel. The UFC’s first charter flight from Las Vegas touched down in Abu Dhabi early Sunday, although Usman was not on it. He decided not to travel upon hearing the news that Burns had tested positive. One of the most popular fighters in the sport, Masvidal was the frontrunner at first to take on Usman, with the pair involved in a heated public feud for some time, only for the former’s pay dispute with the UFC to put an end to negotiations. Masvidal, who last fought against Nate Diaz in November, has been particularly public in his criticism of the promotion, and president Dana White, during the past few months. That prompted White to book Burns against Usman; Burns had won twice since March to propel himself into the No 1-ranked challenger. Should a deal with Masvidal be struck, and the strict coronavirus measures permit the bout to go ahead, it would represent a major rescue act for the UFC. Masvidal is viewed by many as the greatest threat to Usman’s reign. If the bout does not come to fruition, UFC 251 will still feature two stellar title fights, headlined by featherweight champion Alexander Volkanovski’s rematch against former belt-holder Max Holloway. Also on the card, Petr Yan and Jose Aldo battle for the vacant bantamweight crown. UFC 251 kicks of the inaugural Fight Island, and is followed by events on July 16, 19 and 26. All four shows take place at Flash Forum on Yas Island.