Eric Molina leaves his classroom behind to face Anthony Joshua

Texan is taking time off his regular job of teaching children with disabilities and is seeking to upset the IBF world heavyweight champion

Boxing loves a backstory – which is why the sport, for all its faults, remains so captivating. There are tales of redemption, revenge, poverty and pain inside the ring and now comes a rather unusual one to British shores – the Mexican-American heavyweight who doubles up as a special-needs teacher.

Step forward Éric Molina, who takes on Anthony Joshua at the Manchester Arena next Saturday. A relative unknown, the 34-year-old arrived in this country last month not only with an intriguing background but also with the firm belief that he can be the first man to defeat Joshua and take the 27-year-old’s IBF world title. “If I can breathe, if I can stand, I’m going to fight to knock him out,” says Molina. “Other fighters might say that’s what’s gonna happen. I’m gonna show you that’s what’s gonna happen.”

This is fighting talk but, when the fighting gets going, Molina is unlikely to last long. He can punch hard – as Deontay Wilder knows all too well from their bout in June 2015 – but beyond that there is little on offer. Molina is as unrefined as his hulking 6ft 4in physique suggests and Joshua should make it 18 straight knockout victories in next to no time.

In this year of all years, though, it is perhaps wise not to expect the seemingly inevitable and what gives Molina hope that he might produce a sporting miracle, having been brought in by Joshua’s promoter, Eddie Hearn, as a replacement for Wladimir Klitschko after the former three-belt holder picked up a injury in training, is his eyebrow-raising, character-building route to this world-title shot.

Related: Anthony Joshua beats Charles Martin in two to take IBF world heavyweight title

Having taken up boxing at 23 – and only then to lose weight – Molina was knocked out in the first round of his professional debut against Ashanti Jordan in March 2007. He won his next 18 bouts before suffering another first-round knockout, this time by Chris Arreola in his home state of Texas.

Humbled and humiliated, Molina decided to pursue a career outside the ring and in 2012 he earned a masters degree in special education from the University of Texas at Brownsville before going on to teach disabled children at a public school in the city of Edinburg. That appeared that but Molina got the bug to go back into the ring and, spurred on by his promoter – the one and only Don King – he did just that. But the teaching did not stop and Molina combined the two, training twice a day, before and after the day job.

“The world doesn’t really know the story I bring to the table,” he says. “They judge me by one fight, the Arreola fight. You guys could’ve beaten me, I was weak-minded. But I have grown into a dangerous heavyweight and there is no other heavyweight in the world who has gone through the things I’ve gone through.”

It is certainly something to be training for a world title fight at the same time as teaching children with challenging needs, which Molina did before facing Wilder in the WBC champion’s home state of Alabama. “I got off at work at 4.30, trained at five, ran at midnight, went to work the next day, sparred at the weekend,” Molina says and, as with next Saturday’s contest, few gave him any hope of even disturbing his undefeated opponent. But he did just that, wobbling Wilder with a thudding left hook in the third round before being dropped three times en route to a ninth-round stoppage.

Perhaps Molina could have done better had his pre-fight attentions been solely on the fight. But for him teaching is part of his preparations for the ring, fuelling him as it does with a spirit of achieving against the odds. “I love teaching kids with disabilities because they’re underdogs in their lives and I’m an underdog in what I do,” Molina told the San Antonio Express-News last year.

Molina was undeniably the underdog in his most recent fight, against the Polish former two-division world champion Tomasz Adamek – especially as it took place in Krakow – yet he went on to triumph via a 10th-round knockout, subsequently extending his record to 25 (19)-3-0.

Next up is Joshua and Molina’s focus is total – he took a leave of absence from teaching in May, shortly after defeating Adamek. “I’ll definitely go back,” he says. “No matter what happens in this fight my destiny is to work with those kids. They don’t have much opportunities and I’m like a father figure to them. That’s where my heart’s at.

“As a teacher I’m laid-back but that changes when I get in the ring. My family and friends ask: ‘Are you not afraid?’ but the fear inside me is to take a year out of work and put my life on hold for a fight like this. Fighting is fun and, when I get knocked down, I come back even stronger. That’s my story and I like my story.”