Former flyweight king Demetrious Johnson’s tenure in the UFC might soon be over.

According to ESPN’s Ariel Helwani, there is a very high likelihood that “Mighty Mouse” is going to be traded to ONE Championship in exchange for Ben Askren. Which… traded? That’s actually never really been done before at this level.

If you’ll recall, Askren was one of Bellator’s first champs, is undefeated in 19 career fights, and has been spending the last few years clobbering everyone put before him the Asian-based promotion. He’s also been very outspoken about how he could never come to terms with the UFC.

Johnson ruled the flyweight roost for years, but he was never able to spark fan interest, so the division has stagnated. Unfortunately, even though Henry Cejudo is now the champ, it’s possible the UFC will scrap the division when Johnson leaves. We’ll have to wait and see on that one.

Here’s the ESPN scoop:

The UFC and ONE Championship are close to finalizing what could be considered the first major trade in mixed martial arts history.

According to multiple sources, there is a proposed deal on the table for the UFC to release former flyweight champion Demetrious Johnson from his contract in order to allow him to sign with ONE. In return, ONE will release former welterweight champion Ben Askren from his contract so he can finally join the UFC.

Sources say the “trade” isn’t finalized just yet, however, it has been discussed at length and is categorized by multiple sources as close to getting done. All parties involved are hopeful it will be finalized soon.