Artur Beterbiev and Oleksandr Gvozdyk are set to face off in their light heavyweight unification bout on Oct. 18. Check out the fight at 10 p.m. ET Friday on ESPN. (0:50)

Artur Beterbiev faces Oleksandr Gvozdyk on Friday night in a highly-anticipated WBC/IBF light heavyweight unification fight. Beterbiev (14-0, 14 KOs) has become a champion on his own, but the guidance and friendship of MMA legend Georges St-Pierre has led him to greater heights.

Mark Kriegel sat down with Beterbiev and GSP to learn more about their relationship, the strengths of each and what's ahead for two very accomplished fighters in their sports.

Editor's note: This interview has been edited for length and clarity.

MMA legend Georges St-Pierre has become a mentor for boxing champion Artur Beterbiev. Courtesy Artur Beterbiev

Mark Kriegel: How and when did you two meet?

Georges St-Pierre: A long time ago [at TriStar]. I first met Artur, he couldn't speak English, so he had a friend that was translating the conversation.

Kriegel: Why did you guys connect? You're Chechen, you're from Canada, MMA and boxing, what brought you two together?

Artur Beterbiev: For me when I knew him for the first time. He's famous, but he's simple, you know? I can talk with him, I can ask him anything. I asked many things.

Kriegel: What did you ask him?

GSP: We would talk about fighting. He's a boxer, I'm a mixed martial arts fighter, so we had a lot of things in common. If you know about the art of war, the spirit, the mental of the game is pretty, pretty similar, and so I think we developed over time some type of camaraderie, and we starting hanging out. We'd go to a restaurant and his English got so much better since I've first met him. I couldn't really speak to him, now his English is much better.

Kriegel: What did you see in him?

GSP: A fighter. I knew he was like champion material right away in the beginning, but to be a champion and to stay a champion, you know, you need the physicality, you need the mental [toughness]. But you need more than that sometimes; you need to be managed well. You know, I know that because the fighting game, it's not a clean business, you know?

He's a very nice guy with a good heart, and I didn't want to be one of these guys that tried to step into his private life, but I knew for a fact he's a diamond?

Like in the sport, like people will see him, and everybody would try to take advantage of a guy like this because he's so talented. And, you know, I knew it's been done many times in the past, in a country like Canada. In the U.S., they take talent from somewhere else, they bring it here and they take advantage sometimes of people and some of the foreigners. When fighters come from other country, they come to live here, and they're not aware of what is really going on. I want him to have the best life because I do the same thing for a living. It's the hardest job in the world. We put our life on the line every time we step in the ring, that's what he does. He puts his life on the line, and it's very important for me that he's well taken care of.

Kriegel: If Artur Beterbiev didn't meet George St Pierre, where would you be now?

Artur: I don't know.

GSP: Artur would have found a way to do it by himself. If the door was closed, he would have cracked it open and got in. I just maybe opened a door for him to make it a little bit easier to make that path, but I think he's a smart guy. I didn't wanted him to waste his energy and his time because he's a fighter; he doesn't have to focus on that. His job is to fight, he needed to be taken care outside of that. Once you start to waste energy for other things, that's when your career sometimes can take a hit.

play 0:50 Beterbiev set to faceoff vs. Gvozdyk Artur Beterbiev and Oleksandr Gvozdyk are set to face off in their light heavyweight unification bout on Oct. 18. Check out the fight at 10 p.m. ET Friday on ESPN.

Kriegel: What is your goal?

Artur: It's my goal to be a good boxer.

Kriegel: You are a good boxer; you're a champion. Does Oleksandr Gvozdyk give you what you want?

Artur: He's a good opponent, he has good experience. I think it will be a great fight.

Kriegel: You fought 10 years ago, you stopped him in the second round. It was the amateurs. I know you were much younger, but do you ever really forget about someone that you stopped?

Artur: Yes. You have to ask [Gvozdyk] this question, it's not for me. For me, I forget that.

Kriegel: Both fighters would say, "Oh, it was 10 years ago, it's a long time ago, we both got better, be both live in the States now, it's another lifetime ago." Do you ever really forget about a guy who stopped you? Does it ever go away?

GSP: Well, it doesn't go away in a way that you can use that as a motivation to get it back. Maybe he's going to use that as a motivation to get a revenge or something, you know? But, I mean, it's a long time ago. It doesn't mean it's gonna happen again the same way or, you know, it doesn't really mean it.

Kriegel: It's a long time ago, but the four light heavyweight champions all fought together in Russia and Artur was considered by far the best. Does that give you an advantage a decade later here in the States? You, Bivol, Kovalev, Gvozdyk, right? None of them were better than you.

Artur: Once I can repeat again, [there's] only one champion. Not four champions. We need to take all belts, four belts, and after that say, "I'm champion, that's it."

Kriegel: Why are you so disciplined?

Artur: I think it is like from my amateur career, there is a system. You wake up in the morning, you go to training.

Kriegel: Don't you get sick of that?

Artur: I lived like that like for 10, 15 years, on the national team. I think it's because of that. I was in the national team, and I'm different there too, you know, from other athletes. I'm always looking for something. I tried to always do something more, you know. My brother is my first coach and he always tell me, "If you want to be like some good boxer," to catch him you need to do extra. If you finish training, you need to do extra always and maybe I try to do that.

GSP: One thing I've learned with Artur is that in life sometimes you try to get the better thing, the best thing, you know, as an athlete, and he's compelled and he's happy with the simpler pleasures of life -- eating with his family, and he's a happy man. He doesn't need to be the flashy thing that we dream about as a kid. He doesn't need that. He's a happy man with the simpler pleasures of life and that's what I admire of him, and I think it's very important. Sometimes we forget how lucky we are.

Kriegel: What do you need, Artur?

Artur: I need to be one day a good boxer and to be a good father, to be a good son.

Georges St-Pierre announced his retirement from mixed martial arts on Feb. 21, 2019. Jeff Bottari/Zuffa LLC/Zuffa LLC via Getty Images

Kriegel: The first time you retired, Georges, you were younger than he is now.

GSP: Yeah, but I didn't really retire.

Kriegel: Why is it so hard to retire?

GSP: It's very hard because it takes a lot of discipline, because as a fighter we all have the competitive spirit and we always feel like we wanna go again and again and again and again. But the sad truth is that the fighter is always the last person to find out when it's time to retire.

Kriegel: What makes you a fighter also makes you vulnerable at the end.

GSP: Yes, yes, which is a good thing, it's one of our biggest qualities; it's our biggest strength but our biggest issue as well.

Kriegel: You want to look back on your career and say, "I accomplished what I should have accomplished," right?

GSP: Yeah. As a competitor, as a fighter, we're never satisfied with that. I'm never satisfied, and of course if you're satisfied that means it's the end of it. Satisfaction in fighting game is the death, is the end. If you're satisfied, it's over.

Kriegel: What would you, Artur, need to do, to retire? How many belts? How many wins? How much money? What do you need?

Artur: I need to think about it. Right now, everything is good. Of course, boxing is my job, too. Of course, I want to unify.

Kriegel: Do you think your friend has retired really in his heart?

Artur: No, I don't think so. He goes to training every day, you know, he's not really retired.

GSP: The word of retirement doesn't mean anything right now.

Kriegel: But you did retire, you had a press conference...

GSP: Yeah, I did.

Kriegel: And your friend here says in your heart you're not retired. Why?

GSP: 'Cause I love to work out. I'm 38 years old. I try to not be subjective, I try to be objective about this situation.

Kriegel: If the right fight came along ...

GSP: If the right fight came along, they know where to find me. We tried to make the right fight, but it didn't work.

Kriegel: That would be Khabib Nurmagomedov?

GSP: Yes.

Kriegel: Would you come back for Khabib?

GSP: It depends, if everything is aligned contractually, everything is good, as we speak now, yes, I would. But, you know, it's like a business deal, when you make an agreement. When you make a business deal and the guys don't agree, it's OK, you turn around and you do other thing. You cannot come back a year after and say, "Hey, finally the offer that you made me a year ago, I'm gonna take it." That's not how you do business, and the fighting game is no different. If I made you an offer and you refuse, it's fine, but you cannot come back a year after and say, "Oh, finally I'll take it." Before I retired we tried to organize a fight with Khabib. UFC refused, didn't want it, so I walk away, I have other things.

One of the ways the two champion fighters have bonded is through time spent at spas for recuperation. Courtesy Artur Beterbiev

Kriegel: How does your friend Artur finish?

GSP: He finishes on top, he's on the rise. I've been saying for years to everybody here to pay attention to him. It doesn't mean he's not gonna fall one day. Maybe he's gonna take a hit, but he's got a very strong mind. It's not an easy way. Time and life are not a straight line. Maybe he's gonna have some obstacle that he has to [overcome.]

Kriegel: There's a difference, in MMA you talk about a straight line, in MMA the greatest fighter of all can lose.

GSP: Everybody loses.

Kriegel: In boxing there is this expectation that you're supposed to have a perfect record.

GSP: Yeah, but if I sort of look to Artur's record, he always fights the best. He knows he's 35 and he wants to fight the best. He wants to prove himself and he knows that's his time is right now. He doesn't wanna waste time, he wanna fight everybody, challenge Sergey Kovalev, everybody

Kriegel: What happens October 18th?

GSP: Artur Beterbiev will be a champion, and I believe he will do it either by knockout or in the decision.

Kriegel: Two belts for your protégé.

GSP: I really believe it. I think mentally he's so strong. You know, everybody can make a mistake down the road, I believe he's a human being, you know, like anything can happen and it doesn't matter what happens, he's gonna come back and win. I think you have to see your career like a marathon, not like a sprint, and sometimes down the road you make a mistake or something happens and doesn't matter. For me, when I see the big picture of Artur Beterbiev, he's unifying all the titles, and he's the best boxer and champion.