The UFC and the Singapore-based ONE Championship are on the verge of a unique contract swap that will see one of the greatest fighters in the sport’s history leave the biggest MMA promotion in the world.

Sources have confirmed a story first reported on MMA Junkie Radio that former UFC flyweight champion Demetrious “Mighty Mouse” Johnson will have his contract swapped to ONE Championship in exchange for welterweight Ben Askren.

Johnson was considered the pound-for-pound best fighter in the world until his Aug. 4 split-decision loss to Henry Cejudo in a flyweight title fight in Los Angeles. He remains one of the elite fighters in the sport’s history, along with Jon Jones, Georges St-Pierre, Daniel Cormier, Anderson Silva and Fedor Emelianenko.

Johnson’s legendary trainer and close confidant, Matt Hume, is the vice president of operations and competition for ONE FC.

The UFC has long had interest in Askren, but could never come to contract terms with him. Askren has been a frequent verbal sparring partner with UFC president Dana White. On Monday, when asked on Twitter the odds that he’d be in the UFC, Askren wrote, “98%.”

A former Bellator and ONE welterweight champion, Askren’s elite wrestling has made him one of the top fighters in the world for years. Going to the UFC will mark his first opportunity to fight elite opposition each time out.

UFC welterweight champion Tyron Woodley, Askren’s teammate at Roufusport and former collegiate wrestling teammate at Missouri, raved about Askren in a text to Yahoo Sports.

Asked how he felt Askren would do against UFC welterweights, Woodley wrote, “He is a beast and there is no one that will beat him.”

Askren, who is 18-0 with one no-contest as a professional, hasn’t fought since stopping Shinya Aoki in just 57 seconds on Nov. 24, 2017. His most significant wins came in Bellator, when he knocked out Andrey Koreshkov in four rounds in 2013 and won a five-round decision over Douglas Lima in 2010.

Johnson’s loss to Cejudo at UFC 227 snapped a five-year, 13-fight winning streak, as well as a 14-fight unbeaten streak. He’d dominated the division like no other, having dispatched all contenders since winning the belt by beating Joseph Benavidez by decision at UFC 152 on Sept. 22, 2012.

As great as Johnson is as a fighter, though, he struggled to gain traction among the UFC fan base. He wasn’t able to sell pay-per-views or tickets commensurate with his ability and was often frustrated by questions about it.

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