UFC

Conor McGregor is literally puffing his chest at Floyd Mayweather -- showing off the crazy physique he's been training for ... with just days left until the biggest fight of his life.

The Irish superstar posed down at the UFC Performance Institute in Vegas -- saying, "The final rev of the engine on the Conor McGregor Fast conditioning program tonight! What a camp it has been!"

He then got into his green Lamborghini to cool off.

TMZ Sports has put our investigative resources to good use ... and found out the identities of the Corona Girls who've been tapped to work the Mayweather vs. McGregor fight.

You're welcome.

Meet Kyra Keli, Tawny Jordan, Jessica Harbour, and Samantha Kumiko ... 4 of the women who will be working the ring during the August 26 fight.

As we previously reported, Corona won the bid to become the official beer sponsor of the fight and will provide the ring girls.

We're told the women are STOKED -- not only because they're getting the best seats in the house for the fight, but they feel like they'll be showcased to a HUGE audience!

Huge sporting events mean huge money for sex workers ... but cops in Vegas have a message for tourists -- if you're gonna pay for it, KEEP IT LEGAL!

If you like smokin' hot women in bikinis, here's some good news, bad news about the Mayweather vs. McGregor fight ...

Bad news ... the UFC's legendary Octagon girls will NOT be working the event.

Good news ... we're told the Corona Girls will handle ring card duties instead -- and they ain't no slouches!

Here's the deal ... Corona won the bid to become the official beer of the fight -- which means they get prime in-ring promotion, which includes the beautiful women holding the ring cards.

So, what will the Octagon girls be doing on August 26? Hustlin' baby!

We spoke with Arianny Celeste, who says she'll be hosting a fight party in Miami ... and, shocker, she's rooting for Conor.

The Floyd Mayweather/Conor McGregor fight will be riddled with celebrities ... and TMZ Sports knows some who will be front and center.

Here's a partial list:

-- Angelina Jolie

-- Drake

-- Elon Musk

-- Diddy

-- Mark Wahlberg

-- Denzel Washington

-- Charlize Theron

-- LL Cool J

-- Jamie Foxx

-- LeBron James

-- Bob Kraft

-- Rick Ross

-- Adam Levine

-- Michael Bay

-- Avicii

-- Jeff Beacher

Daniel Cormier just rejected Jon Jones' friend request -- but the good news ... it sounds like they don't hate each other as much as they used to.

Remember, the animosity between the two was legendary -- they trashed each other for years in public and in private and called each other every bad name in the book.

But after Jones defeated Cormier at UFC 214 in July, JJ offered the olive branch -- and then told TMZ Sports he hoped the two would be friends one day.

Well, Cormier finally responded Wednesday night on FS1's "UFC Tonight" -- and politely declined the offer.

"Friendship would be very difficult for us to achieve because of our history," Cormier said ... "And I'm okay with that. I've always said that we don't have to be friends."

Cormier says he respects Jones as an athlete -- and still wants another rematch.

"In terms of going forward, we will be professional because we have to ... until the cage door closes again."

Floyd Mayweather Sr. is coming out swingin' at Justin Bieber -- saying the pop star doesn't know a DAMN THING about boxing if he thinks Conor's gonna go the distance.

Remember, Bieber -- Floyd Jr.'s longtime friend -- recently shot down the idea that Mayweather would K.O. McGregor ... and that ain't sittin' too well with Floyd Sr.

"Justin Bieber ... he don't even know boxing," Floyd's dad told us at LAX ... "He knows Floyd. But he don't know Floyd like I know Floyd."

Floyd Sr. also went in on Vegas gamblers putting their money on Conor -- saying they're crazy ... and a bet on Floyd is like taking free money!

Floyd Mayweather says he's putting business before pleasure -- and won't have sex before he fights Conor McGregor.

It's an old superstition that's been around the boxing game for years. You remember Mick from the 'Rocky' movies famously said, "Women weaken legs."

Floyd seems to agree. Conor McGregor has a different strategy.

"That is most certainly a superstition that I do not abide by," Conor told Conan O'Brien back in 2015 ... "I definitely have as much sex as possible."

So, to bang or not to bang? That is the question ...

They thought they were slick ... dozens of websites aiming to livestream the Mayweather vs. McGregor fight for free.

But Showtime is preemptively striking the potential pirates with a big, fat lawsuit ... mateys.

The network is ripping a page from the Mayweather vs. Pacquiao playbook -- where they scouted out a bunch of potential illegal streaming sites and hit 'em with a legal blow before the fight.

There's obviously a TON of cash on the line -- some say the fight could bring in more than $500 MILLION ... so, they ain't lookin to let anyone skim from their pockets.

In the suit, filed in federal court, Showtime is asking a judge to issue an injunction to block the sites from streaming the August 26 fight -- and they'll probably get it.

Even Floyd Mayweather's closest friends don't think the boxer has a real shot of knocking out Conor McGregor next weekend ... just ask Justin Bieber.

Mayweather told the media last week he's gunning to finish the UFC star long before the 12th round when they clash on August 26. Tons of boxing experts are also predicting a K.O.

But not Biebs.

The singer hit up Runyon Canyon for his own workout when he poo-poo'd the knockout talk -- though it's clear he's still pickin' Floyd to get the W.

Bieber's been hardcore Team Mayweather for years -- and even walked the boxer into the ring for the Pacquaio fight.

Jon Jones says he's a fool for passing up a chance to hang with Muhammad Ali ... and tells TMZ Sports the regret's still eatin' him up.

In a few words -- "That really sucked."

Jones has met a who's who of legendary fighters in his life ... but told us he backed out of a dinner with The Greatest cause he was afraid to see one of his heroes in such a bad way.

Ali battled Parkinson's for years and one of his friends advised him not to meet with his hero because Ali was a shell of his former self and "it won't be everything that you thought it would."

Cody Garbrandt better watch his back ... 'cause one pissed off contender is ready to put him in a body bag.

That man's Aljamain Sterling ... who told the guys on TMZ Sports (weeknights on FS1) he's coming hard after Cody 'cause the UFC champ took a shot at him after a rough loss -- saying Alj "broke" in his fight with Bryan Caraway.

"Eventually he's gonna have to meet his maker. That maker's gonna be me," Sterling tells us.

Sterling's coming off a HUGE win over former bantamweight champ Renan Barao ... but tells us he has another guy on his hit list before he takes out Cody.

Paige VanZant won't let a massive bloody wound keep her from fighting -- she's already stitched up the gash on her foot and got back on her grind.

The UFC superstar opened up a gnarly hole in her foot on Wednesday -- but one day later, she was back working out ... hitting a set of crunches with a fresh set of stitches.

VanZant is rumored to fight Jessica Eye at UFC 216 in October -- and at this point, it doesn't appear she's gonna let the injury keep her out of the Octagon.

WARNING: This is pretty gnarly. And bloody.

UFC star Paige VanZant tore a massive bloody hole in her foot -- and the photo is pretty graphic.

23-year-old VanZant didn't say how it happened ... but with rumors she could return to the Octagon at UFC 216, it's likely she opened the gash during a training session.

Pretty gross ... but this kinda stuff happens.

UFC 216 is scheduled for Oct. 7 -- and reports say PVZ will likely fight Jessica Eye.

Jon Jones just answered a fundamental question ... can you be friends with a guy who accused your penis of being broken in front of the whole world?

Apparently the answer is yes, 'cause Jones told TMZ Sports he actually wants to be pals with Daniel Cormier now that their superfight is history.

These two guys seemed like they freakin' hated each other, and exchanged legendary insults ... Jones calling DC fat, and DC accusing Jones of "sandblasting prostitutes" and having a defective manhood.

Still, when we got Jones in NYC and asked him if things could ever be gravy between the two men, Bones seems like he was down for a truce.

"I would definitely like to have a respectful relationship with Cormier. It would be great to support each other's causes, charity events and maybe do an interview together and talk about one of the biggest rivalries in combat sports history."

Will it happen? Jones isn't convinced, and there's a really good reason why.

"I don't think he feels the same way."

Chuck Liddell vs. Chael Sonnen ain't happenin' just yet ... but the Iceman hinted that the legends fight could go down -- if the money's right.

We got Chuck at LAX ... and the UFC Hall of Famer fired his first shots at Chael after the MMA great teased the OG throwdown last week ... saying Liddell would be his next opponent.

Iceman told us Sonnen would get SMASHED even though he's been retired 7 years, saying, "He's an easy matchup ... He ain't gonna take me down and lay on me."

Chuck also called Chael boring ... but says the fight would do big business anyway.