Conor McGregor's next opponent will likely come from this group

Should White let McGregor box again? (1:56)

Stephen A. Smith and Max Kellerman debate whether Dana White should let Conor McGregor box again after his match against Floyd Mayweather. (1:56)

The Floyd Mayweather-Conor McGregor Summer Spectacle is officially over after culminating in a fight that was actually quite enjoyable.

Congratulations to us, right? We boarded the fanciest, flashiest train in the station with no real idea of where it was going, and it ended up working out for everyone in the end. High-five.

So, now that that's over ... what's next?

For the wealthy, undefeated Mayweather, it's retirement. He says he's done at age 40 and -- for now -- there's no reason to not believe him.

McGregor (21-3), of course, is a different story. The UFC's 29-year-old lightweight champion has options when it comes to his next fight. Here's a list of the four most likely combatants he's looking at.

The Nate Diaz trilogy

To date, Diaz has been McGregor's most natural rival -- and that may never change. These two were made for each other in many ways. It's a proven seller, and it's tied at one apiece.

McGregor wants to do a third fight, and basically has ever since Diaz (19-11) choked him the first time they fought. He promised revenge in a rematch, and eternal bragging rights in an eventual rubber match.

After McGregor evened the score at UFC 202 one year ago, there was no need to rush a third fight. He had other options: A second UFC championship and, then out of nowhere, came Mayweather.

Today, this matchup feels fresh again and it's probably the biggest fight McGregor can book as far as fan interest. This would seem like the most likely option, perhaps on Dec. 30 in Las Vegas.

The very much deserving Tony Ferguson

Not just "very much deserving." The "most deserving."

If McGregor's opponents were booked on merit alone, Ferguson would unequivocally get the nod. He's on a nine-fight win streak, and he's been willing to put that win streak on the line multiple times in 2017 as he "waited" for McGregor to box.

The fact that it never happened (Ferguson hasn't fought since last November) is not his fault. He was supposed to fight Khabib Nurmagomedov in March, but Nurmagomedov fell off due to a bad weight cut. He then wanted to fight Diaz in July, but Diaz couldn't reach a deal on his end with the UFC.

Now, Ferguson (22-3) has accepted a very dangerous interim title fight against Kevin Lee in October. If he wins that, it'd be a crime to deny him McGregor -- but one can definitely see that happening.

Ferguson has the best case to fight McGregor, but not the best chance at doing so right now.

The enigmatic Khabib Nurmagomedov

There is all the potential in the world for a classic McGregor/Nurmagomedov rivalry. We're talking made-for-Hollywood type stuff here. Whether it all comes together is up to Nurmagomedov.

Nurmagomedov (24-0), from the Russian Republic of Dagestan, is cold, undefeated and has a large Russian fanbase. His fighting style perfectly clashes with McGregor -- as does his promotional style. Picture a man who would respond to McGregor's verbal warfare with evil laughter -- and to his left hand with overwhelming offensive wrestling.

We could have a whole lot of fun with this bad boy, but Nurmagomedov be playing. He (tragically) pulled out of that Ferguson fight in March, and that's been an unfortunate trend in his career.

Whether it's bad luck or of his own doing, Nurmagomedov has been pulled from several big fights in recent years. It's prompted McGregor to label him a "pullout merchant" and made it difficult to build the hype that could characterize a fight between these two.

It seems unlikely Nurmagomedov would draw McGregor in his return to the UFC.

The Paulie Malignaggi situation

You thought you were going to avoid this one, didn't you? No sir.

Everyone knows this story by now, right? Awhile back, Malignaggi, a retired two-weight world boxing champion, made a few negative remarks on McGregor's chances in a ring. When McGregor signed to fight Mayweather, he invited Malignaggi to Las Vegas to spar.

They went 20 rounds and, apparently, became sworn enemies. Leaked photos. Knockdown controversies. Malignaggi split, then resurfaced fight week. There was a face-to-face confrontation. Just, bad blood. Bad blood, everyone.

So, is this enough to actually produce something in the ring?

My answer to that is "yes," -- but not now. McGregor keeps his options open, but it would be very surprising if his next fight wasn't in MMA. Down the road, if he does want to box again (or feels it's the biggest fight out there), Malignaggi is a sweet look for an opponent because the storyline is there and he's not at the very top of his game anymore. But not right now.