Floyd Mayweather Jr. and Conor McGregor tie up during their...

Floyd Mayweather Jr. and Conor McGregor tie up during their super welterweight boxing match on Aug. 26, 2017 at T-Mobile Arena in Las Vegas. Credit: Getty Images / Christian Petersen

Curtis “50 Cent” Jackson plays a tough guy in the movie “Den of Thieves,” which premieres on Jan. 19. But then again, pretty much everyone in the action/caper movie plays a tough guy.

The rapper/actor/businessman also plays a tough guy in real life, though, as evidenced by his claim that he could take mixed martial arts star Conor McGregor in a street fight.

Hmm. Jackson first made the claim in September. He did not back down on Monday when asked during an interview to promote “Den of Thieves” whether he still feels that way.

“Right now,” Jackson said, accepting the challenge. “When he’s at 154 pounds? (McGregor weighed in at 153 for a boxing match against Floyd Mayweather Jr. in August.) I’m 225 right now!

“They don’t understand this is heavyweight [expletive] going on around here. I hit them, they see a white light. They hear a message. Slow down, boy. They think Jesus is talking to them.”

Jackson indeed is significantly bigger than McGregor, and he boxed in his youth. But he also is 42 to McGregor’s 29, and he is not a professional fighter. McGregor is the reigning UFC lightweight champion and also won the featherweight title before having to vacate it.

That would not matter in a battle “outside the confinements of the sport,” Jackson said. “If you got into a [street] fight, it’s a different thing.”

During a news conference last year to promote the Mayweather fight, McGregor made reference to Jackson’s financial troubles. It was one of his many efforts to poke at Mayweather, with whom Jackson is close. Jackson was not amused.

Mayweather beat McGregor on a 10th-round technical knockout, but McGregor widely was praised for how competitive he was against the boxing champion.

“Tough as nails,” Jackson said of McGregor. “I wouldn’t fight him at 150 – wouldn’t even square up with him. I’m not doing that, with Floyd either. Weighing 150, I would not do that . . . I just think the advantage of being bigger would benefit me in a fight with a guy that’s 150 pounds. That’s pretty small. I was 150 pounds at [age] 13.”

McGregor has fought as high as welterweight (170 pounds) in MMA.

Jackson said he is a fan of mixed martial arts, and on the set of “Den of Thieves” he met two pros, Max Holloway and Michael Bisping, who have small roles in the film. Holloway is the reigning UFC featherweight champion, and Bisping lost his middleweight title last November.

Jackson got into the boxing promotion business in 2012, but his company filed for bankruptcy in 2015.

“The promotion part of the sport is not a place that I would pick for business purposes,” he said, “but the passion for the sport and to be around it is exciting for me. I would commit to doing things for marketing around actual projects, but being the promoter is not the best job.

“It’s easy from the viewpoint of Floyd being at the top of it. But the whole rest of the sport, it’s like, he is the sport. If you took everything else that happens in the sport, everything growing, everyone coming out, and you looked at what their revenue was, what their earnings are, him by himself when he gets ready to fight is bigger than the entire sport.”

Jackson said he prefers the UFC’s business model. “They can make the fight that everyone wants to see,” he said. “The UFC still hasn’t done the numbers that the sport of boxing has done when Floyd is fighting, but the promoters in the sport of boxing, they can hide their fighters.”

Jackson said he has become more comfortable as an actor and plans to continue doing more such work.

In a rare comedic scene in “Den of Thieves,” he is shown introducing himself to his teenage daughter’s date, then taking the date into his garage to introduce him to his intimidating friends as a warning to treat his daughter respectfully. Or else.

“It was cool,” he said of the scene. “Certain things you would hope you can communicate with your kid. It’s a really volatile point in their decision-making. Instincts kick in . . . It could very well go down. I’m like, come here and let me talk to him for a second. You know how many people identify with that?”

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