Five Rounds: Urijah Faber talks Conor McGregor-Floyd Mayweather, BJ Penn's IV treatment an more

— -- Each week, ESPN.com writer and MMA Live Extra analyst Brett Okamoto provides his take on the hottest topics in the world of mixed martial arts.

This week, Okamoto squares off with UFC bantamweight Urijah Faber to debate the latest news and trends. Faber (33-8) returns to the Octagon to face champion Dominick Cruz on June 4 at UFC 199 at The Forum in Inglewood, California.

1. Will Conor McGregor's next fight take place in the UFC and will it be against Nate Diaz?

Faber: I've been seeing a lot about the boxing world as of late. Sounds like Conor could get paid a pretty penny to go box, and he's a pretty good boxer. He's a bigger guy, younger guy than Floyd Mayweather. Sounds like that might happen, so kudos to him if it does. I hope he comes back to MMA. We love Conor in the MMA game.

Okamoto: I believe the answer to both questions is still "yes." It's not a done deal, we know that. UFC president Dana White and CEO Lorenzo Fertitta flew to Diaz's hometown last week and attempted to iron out a deal, but to use White's words, it "wasn't a good day." That doesn't mean the fight is dead, though. Diaz agreed to fight McGregor at UFC 200, and now, after everything that has happened between McGregor and the UFC -- a very well publicized civil war -- Diaz is probably thinking their rematch is an even bigger deal than it was before. So it would seem he wants to be paid more for it. It's hard to predict fight negotiations, but ultimately, McGregor would like to fight Diaz, Diaz would like to fight McGregor and the UFC would obviously like to promote that fight. To me, that's the most likely outcome, but it's a fluid situation.

2. Do you believe the widely speculated boxing match between McGregor and Floyd Mayweather is real?

Faber: I'd have to talk to my lawyer and ask, but here's the question: Can somebody play water polo, be under contract with a league, and then jump over and play horse polo, you know? They're two different sports. It just depends if the UFC has him exclusively, in fight sports in general. Could he go compete in a jiu-jitsu tournament? I know guys who have been under UFC contract and done Brazilian jiu-jitsu competitions for a cash prize. Is that the same thing? I think the UFC will fight tooth-and-nail to keep him with them. I'm not sure on the legalities of things. But if they can't enforce him only fighting in the UFC, then I think for sure it could happen. If these guys want to fight, let them fight. ( Note: Asked what his gut tells him about whether the fight will happen, yes or no, Faber replied, "Yes.")

Okamoto: When it first surfaced, ESPN boxing writer Dan Rafael and I torched it as a completely nonsensical fantasy. I'm willing to admit that, sitting here today, I'm taking it slightly more seriously. But as Faber points out, it would come down to either the UFC giving McGregor permission to box or McGregor finding an out in his contract -- perhaps a legal argument that the UFC holds exclusive rights to him only in mixed martial arts, not other combat sports. I personally haven't seen McGregor's contract, but I have seen other UFC contracts, ones that explicitly state that the contracted athlete cannot box. So I guess in a nutshell, my feeling on the matter comes down to this: Do I believe it's possible McGregor would be interested in a boxing match against Mayweather that would pay him an obscene amount of money? Yes. Do I believe it's possible Mayweather would be interested in a boxing match against McGregor that would pay him an obscene amount of money? Yes. Do I see the fight happening? Still no, but I'm not dismissing it like I did previously.

3. What did you make of BJ Penn's recent violation of the UFC's anti-doping policy (use of an IV), and could it ultimately prevent his comeback entirely?

Faber: So, I don't know if I know the details. I saw a little blurb on it. I hope it doesn't prevent his comeback. I love BJ, and I love watching him fight. I wish the best for him. It all sounds very strange to me. As far as IVs, we've all been taking IVs for a long time because it wasn't illegal, so it's just weird to me they would stifle somebody's opportunity for taking an IV, especially far out from a fight. I don't know what that means or why it matters, but I'd love to see BJ come back, and I hope he does. I would seriously, seriously doubt that BJ would be taking performance-enhancing drugs. I've had discussions with him about it. I think he's on the same page as I am about what that means to have to take that stuff. That means you're mentally weak, in my opinion. I don't see that with BJ.

Okamoto: I don't think it will prevent his comeback entirely. Of course, a lot of that probably hinges on what type of punishment he receives. There are some pieces of this story currently missing, but we can reasonably assume, based on the timeline of events, that Penn admitted to using an IV back in March. At that point, USADA probably informed him he was facing a possible violation, but if he could demonstrate a medical need for taking an IV at that time, he might be eligible for a retroactive therapeutic-use exemption, meaning he'd be off the hook and still be able to fight at UFC 199. Since the UFC was forced to pull him from that event, we can assume Penn didn't fulfill his requirement for an exemption. I'd be curious to know why Penn was using an IV back in March. He hasn't explained that part yet. Either way, this most likely comes down to how long he's out. I wouldn't expect it to be terribly long, and if it's not, it seems likely to me he'd still want to fight once it's over.

4. Was Michael Bisping the right choice to replace the injured Chris Weidman in next week's UFC middleweight title fight against Luke Rockhold at UFC 199?

Faber: I think so. [ Ronaldo "Jacare" Souza] had a hurt knee, and I think Bisping, that guy has been so close to title shots his entire career and he's still improving. You see him improving. He's coming off a big win over Anderson Silva, I mean, how many people can say that? So, giving him an opportunity -- you never know what's going to happen. I've gone into fights where I've been injured before. You don't know what guy you're getting on the other side in this sport, and you don't know what you're capable of, so I think he's a guy that everybody knows, he's had his eye on this prize for a long time, and it does make sense.

Okamoto: 100 percent, yes. Once Souza was ruled out because of a knee injury, Bisping was the obvious choice. I would guess most of us had come to the assumption this day would never come for Bisping. Nearly one full decade into his UFC career, it just wasn't meant to be. Most of us felt happy for him to simply get a non-title headliner against a former champion in Silva earlier this year in London. Bisping's had a phenomenal career. He has been deserving of a shot before, and the timing didn't work in his favor. He has lost key fights to opponents who later failed drug tests for performance-enhancing drugs. This opportunity was owed to him. Win or lose, I'm personally willing to say I'm happy to see him get this shot. It would have felt like a "wrong" had been committed had Bisping never fought for a UFC title.

5. Fabricio Werdum wants an immediate rematch against newly crowned UFC heavyweight champion Stipe Miocic. Does he have a case?

Faber: You know what, I never argue with anybody's opportunity. If he gets it, I think yeah. If he doesn't, he shouldn't be complaining. I, uh, I don't care.

Okamoto: You know, he actually does have a very strong case in my opinion. That doesn't mean he'll get a rematch. In fact, I'm more or less positive he won't. But if you want to talk about resumes over the last two or three years, no heavyweight has done what Werdum has. And although Miocic deserves full credit for knocking Werdum out stiff earlier this month in Brazil, I did feel somewhat robbed after that fight. Werdum made a terrible mistake and sprinted after Miocic with his guard down. I mean, what was that? I'd be interested to see a rematch between the two, one in which Werdum does not offer his chin up on a silver platter. So, yeah, he has a case, but at the same time, he wasn't a dominant champion. As much as we can point to his mistake in that fight, that doesn't erase the fact that it was extremely convincing and completely void of controversy. Miocic vs. Alistair Overeem is the heavyweight championship fight to make. That's just the unfortunate truth if you're Werdum.