The UFC and ONE Championship are on the verge of a "trade" that will ultimately send Demetrious Johnson, the UFC's longest-reigning champion of all time, to ONE in exchange for undefeated welterweight Ben Askren.

Askren (18-0) is a former NCAA Division I national champion wrestler at the University of Missouri. A former Bellator MMA champ, he tried to sign with the UFC five years ago but couldn't strike a deal with president Dana White.

The 34-year-old has been at the center of debate throughout his career. Askren has fought some tough competition -- including Douglas Lima and Andrey Koreshkov -- but until now, the question of how he would fare against the UFC's roster has been left to speculation.

Should the deal become official and Askren finally makes his Octagon debut, whom should he fight first? Here are the top three options:

Georges St-Pierre last fought in November 2017, when he defeated Michael Bisping by submission to win the UFC's middleweight title. Jeff Bottari/Zuffa LLC/Zuffa LLC via Getty Images

Georges St-Pierre

Honestly, my list kind of starts and ends right here. This wouldn't be the only option for Askren (there are plenty of good ones), but it would be the perfect one.

Askren sort of has the reputation of a trash-talker, but that's not the best way to describe him. He's not one to spout off one-liners, but he has a sense of humor and is unapologetically direct.

He has a lot of respect for St-Pierre and he wouldn't stick his finger in his chest like Michael Bisping did a year ago, but Askren would not overly respect him. He would be genuinely confident going in, and that would come across in any prefight interactions.

Would St-Pierre take this fight? Earlier this year, he basically said he would not, because Askren's stock isn't high enough. He's too much of an unknown. But one could argue that Askren's stock might never be higher than it is right now. There's value in the unknown. There's value in this: undefeated American champion, who fought overseas the last five years but the UFC has orchestrated a historical trade for, parting ways with the great Demetrious Johnson, just so fans can see him face Georges St-Pierre in the Octagon.

Tell me that's not a compelling narrative to sell a fight on. This is the one, guys.

Oh, and Askren is most definitely on board with this.

Hey @GeorgesStPierre please name your terms of engagement!!! Who would you like me to beat up or how many twitter followers would you like me to have. You name it's done. Then I'll see you in Montreal. - Ben Askren (@Benaskren) October 26, 2018

But @GeorgesStPierre please be specific, ambiguity sucks. I know you like a challenge and I am a puzzle you have never solved yet. - Ben Askren (@Benaskren) October 26, 2018

Could a Tyron Woodley fight be first for Ben Askren? Andrew Hancock for ESPN

Tyron Woodley

It's not gonna happen -- but if we're listing the top options, this has to be included.

Askren and Woodley, the UFC's welterweight champion, happen to be teammates and friends. Their connection dates back to the wrestling mats at Missouri.

Could you imagine if Askren suddenly came out and challenged his buddy? I love ya, Tyron, but that's my belt you've been holding. The betrayal! And if we really want to find out how good Askren is, what better way than have him face the absolute top of the division.

Fun to think about, but not gonna happen. Moving on.

Kamaru Usman faces Rafael dos Anjos on Nov. 30. Jason Silva/USA TODAY Sports

Kamaru Usman

This would be contingent on Usman beating Rafael dos Anjos on Nov. 30 in Las Vegas.

Stylistically, there aren't many secrets to Askren's game. It's dominant and predictable. His wrestling prowess overwhelms opponents, to the point his fights are frequently characterized as "boring" by some of the MMA fan base.

Usman, a former collegiate wrestler himself at University of Nebraska at Kearney, has occasionally faced similar complaints about his style. He's a strong grappler as well, and has long claimed he's one of the "most ducked" fighters in the UFC because of that.

Pitting a confident, outspoken Askren against an opponent who is a tough fight for him on paper and has the reputation of a guy no one wants to fight would be really interesting. The new guy coming in to take on the avoided guy. I can get behind that.

Again, Usman needs to get past "RDA" first. If he does, he'd be 9-0 in the UFC.

But wait ... there's more

Even though those were my three choices, Askren has been vocal on Twitter, calling out other potential UFC opponents:

And @TeamKhabib I'll meet you at 165 to determine the best MMA grappler on planet earth! You just name the time and send location. - Ben Askren (@Benaskren) October 26, 2018

And @NateDiaz209 you can't keep waiting on your sugar daddy @TheNotoriousMMA to make you some more money. If big bro lets you out of the house and your feeling funky holler at me - Ben Askren (@Benaskren) October 26, 2018