Chris van Heerden left South Africa and moved to the United States, leaving behind the comfortable life he’d built to pursue a dream of becoming a major player in boxing.

His is a story not unlike millions of immigrants over the years, many of whom made it, others of whom did not.

Van Heerden’s dream, though, differs significantly from others because of a chance encounter with a mixed martial arts fighter.

And in the process, he unexpectedly found himself in the middle of a media storm.

The 30-year-old is 25-2-1 with 12 knockouts. The most notable name on his resume is budding superstar Errol Spence Jr., the IBF welterweight champion who stopped van Heerden in the eighth round of a scheduled 10-rounder on Sept. 11, 2015 in Toronto.

His life changed, though, when he met UFC lightweight champion Conor McGregor and had two sparring sessions with him. It came just prior to McGregor’s rematch with Nate Diaz at UFC 202 last year.

He said he was asked by owners of a Southern California gym to spar with McGregor, who will fight superstar boxer Floyd Mayweather Jr. on Aug. 26 in a pay-per-view show that could break the all-time sales record.

There were two sessions over a period of four days last July, van Heerden told Yahoo Sports.

“I was approached by the gym owners and I made it very clear that I didn’t want any footage out there,” he said. “I was out of shape, I’d just come off holiday and I was just trying to help Conor. He didn’t pay me one dime, not one dollar. He just asked me if I could move around with him, because at that time, he was getting ready for the rematch with Nate Diaz and he wanted a big southpaw to work with.

“Me being from South Africa and coming to America, I knew the first thing people were going to ask was, ‘Who is this guy Conor is working with?’ That was around the time the whole Mayweather-Conor thing got serious. I saw the marketing aspect of it, but Conor didn’t pay me and I helped him. And that first occasion was beautiful.”

Life changed for van Heerden after the second, three days later. A video crew showed up with McGregor, who at that time held the UFC featherweight title.

Van Heerden again said he reiterated that he didn’t want video of the session publicly released because he was still working his way into shape.

“The gym owners asked me if they could film it and I’d made it very clear my position, that I didn’t want anything out there,” he said. “This wasn’t about me beating him up or him beating me up or whatever. I was just getting back in the gym and I was just helping Conor.

“An hour later, my phone started crashing. I looked at my phone and I saw this footage on TMZ. I asked the gym owners and they said, ‘We asked Conor because it would be good for the gym.’ ”

He wasn’t thrilled, but he was dealing with it. A few days later, though, van Heerden was angry. He said McGregor released edited footage of the sparring session that van Heerden says didn’t reflect what happened.

It was made to look as if McGregor was beating van Heerden up, and it didn’t sit too well with van Heerden.

“You can imagine the press: Everyone was killing me,” van Heerden said. “I’m from South Africa, sir, and I came to America hoping to follow my dreams. Conor put that edited video out and it made me look bad. I told him, ‘I don’t appreciate that. I was doing you a favor, because I’m not your sparring partner and you didn’t pay me. I did you a favor because you asked me to help you.’ ”

So van Heerden has released the entire footage of their sparring session in an attempt to clear the record, so to speak.

Van Heerden and manager Peter Kahn are working to get onto the Mayweather-McGregor card, and hope to fight WBA welterweight champion Lamont Peterson. Van Heerden is ranked 11th by the WBA, 14th by the WBO and 15th by the IBF.

“Chris absolutely deserves a world title shot,” Kahn said. “His only loss at welterweight is to Errol Spence Jr., arguably the best welterweight in the world. While we were in Sheffield for Brook-Spence Jr. Errol told me Chris was his toughest fight to date. No one wants to fight Chris. Believe me, I’ve served up win-win scenarios for Al Haymon to make the Peterson fight which includes bringing our own purse to the table. No one in the top 15 wants to fight Chris because he is a tough fighter to fight. Plain and simple.”

But while chasing a high-profile fight of his own, van Heerden hasn’t held back his opinion of McGregor’s boxing skills. McGregor has never had an amateur or pro bout and the consensus is that Mayweather will win their fight easily.

Van Heerden made points on both sides for McGregor.

“I’m a guy who calls a spade a spade and I don’t touch stars or anything like that,” van Heerden said. “Conor’s boxing skills did impress me. Let me tell you that. His boxing skills did impress me as far as him being an MMA fighter. I was like, ‘Oh, his boxing is really not that bad. He knows a little about boxing.’

“The bad aspect for me is his precision and his timing. He’s got a good eye. He’s all over the floor. His footwork is not good, but he’s a mobile guy. As I said, he’s got a good eye and a good counter left hand.”

Van Heerden described McGregor as “nothing but humble and nice,” but said he doesn’t see how he has a chance to win the fight with Mayweather.

He noted they wore headgear and 16-ounce sparring gloves, but said McGregor’s vaunted punching power was negligible.

Asked to compare McGregor to Spence, van Heerden chuckled.

“You have to take into account that I had the big gloves and headgear, but I’m going to tell you straight up, I wasn’t fazed at all by his power,” van Heerden said. “He was a lot bigger than me, I’ll tell you that. He was a big boy. I’m not going to lie, but I honestly wasn’t fazed by his power at all. At all. I fought Errol Spence and that was a fight versus this being sparring, but there was a tremendous difference there.”

He said he feels he was done wrong, but says he has no hate for McGregor and hopes promoters include him on the show.

He said while he respects McGregor, he sees little reason to believe he has a chance against Mayweather.

“What I think is going to happen in this fight is that Conor McGregor is going to box with Floyd and try to prove to people that he is a boxer,” van Heerden said. “That is the biggest mistake he can make because you cannot outbox Floyd Mayweather. You just can’t. He will make you look silly. He’ll make you miss. He’ll literally make you look silly.

“Floyd is going to hit him and Floyd is going to catch him over and over and over. Floyd will make him miss so badly and I think Conor is going to get so frustrated that he’ll let his hands drop and come with his mixed martial artist’s power. He’ll drop the hands and Floyd will beat him up so badly, they’ll stop the fight.”

More Mayweather-McGregor coverage on Yahoo Sports:

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