Conor McGregor returns to Las Vegas for a rematch with Nate Diaz, but though the two names topping the bill are the same, everything else in mixed martial arts has changed utterly.

Since McGregor tapped Diaz twice on the arm to concede defeat for the first time in the UFC back in March, the fight game has been turned upside down.

The UFC itself has been sold for a reputed €4 billion (€3.5 billion), and the cold hand of Usada has caught out high-profile stars like Jon Jones and Brock Lesnar for doping.

It's flagship 200th event was saved from ignominy by Amanda Nunes' shock victory over Miesha Tate, a win which gave this most macho of organisations its first openly gay champion.

There are even serious moves afoot to organise the fighters into a union that would seek to raise their paltry share of the enormous revenues that made the UFC a takeover target in the first place.

But nothing has changed more than McGregor himself. He has retired, come back and completely changed his preparations as he seeks to avenge his defeat to Diaz and resume his battle for control in the UFC.

Much is made of the steep arc of McGregor’s progression from penniless hopeful to top billing in one of the fastest growing sports in the world, but his preparations for this rematch and his mastery of the PR game have arguably made him more dangerous than ever.

When McGregor asked to be relieved of some other PR burden for UFC 200 his request fell on deaf ears, leading to him being unceremoniously booted off the bill. The UFC slapped him down, leading to a retirement announcement from McGregor that was as hot-headed as it was short-lived. When the dust settled, McGregor set out to do to the UFC what he did to his opponents in the octagon – dominate them.

Since a new date was fixed for the Diaz fight, McGregor did what he was contractually obliged to do by the UFC media machine, but very little else.

In fact, he has done everything he can to test the boundaries, and their patience.

In contrast, the affable but often incoherent Diaz did the rounds of the talk-show sofas, where much of the talk was inevitably about the fighter who wasn’t there.

Rather than do the UFC's public relations bidding, McGregor launched his own website, The Mac Life, to give fans an inside look at his life and training, draining viewers away from the UFC's official channels in the process.

Four-letter words

This week, McGregor arrived almost half an hour late to the UFC’s pre-fight press conference and spoke for a few minutes before it ended as a flurry of four-letter words as bottles and cans were hurled between McGregor’s camp and that of Diaz.

The whole episode left UFC kingpin Dana White standing at the podium looking like a teacher who had lost control of the classroom.

Though he will have been secretly delighted at the uproar, which no doubt will give ticket and pay-per-view sales a boost, he made no effort to hide his frustration with McGregor’s tardiness.

As ever, McGregor doesn’t care and will go on suiting himself.

Famous for preparing for fights rather than specific fighters, the 28-year-old has taken a completely new approach for this one, seeking to recreate Diaz as closely as possible in his sparring and grappling partners.

McGregor is also well aware that it was ultimately his physical conditioning that failed him in March, and he will arrive at the T-Mobile on Saturday prepared to go the full five rounds and then some in search of redemption.

Much is made of the fact that Diaz is a black belt in Brazilian jiu jitsu but his boxing should not be underestimated.

It was his left hand that stunned McGregor, and with the Irishman lacking the lungs to recover, that blow ultimately led to the rear-naked choke that gave Diaz the victory.

Knockout specialist

That said, for all his boxing prowess Diaz is not a knockout specialist, with only four of his 20 wins coming via that route. Submissions account for 12 of those victories, and of his 11 fights that have gone the distance, he has won the decision only three times.

Those statistics would suggest that McGregor’s tactic should be to keep the brash Californian on his feet for as long as possible and be prepared to go the distance, but McGregor always fights going forward.

Whatever happens, McGregor will either have to defend his featherweight crown soon or give it up, and a trilogy fight against Diaz is already being mooted.

But a win over Diaz would mean much more than just redemption for McGregor – it would give him the upper hand over White and the UFC, and the chance to further shape the fight game for years to come.