He emerges like Rambo from the mud. Fiorentina centre-back Facundo Roncaglia is yet to cross enemy lines. He is still in his own half of the pitch when he launches a ball towards the Napoli penalty area. As it travels through the air, all it needs is the video game sound effect of a grenade. Panic spreads.

Napoli goalkeeper Morgan de Sanctis doesn’t know what to do. Should he stay? Should he go? Thinking, like his defenders Miguel Britos and Hugo Campagnaro, that Fiorentina striker Luca Toni might get a head to it, he decides to go. It’s a mistake, a big mistake. Taking their eyes off the ball, all of them have misjudged its trajectory and look on in despair as it sails past their heads and into the empty net.

Rather than put the goal down to an error of judgement on de Sanctis’ part, which drew comparisons with that made by another Napoli goalkeeper, Claudio Garella, at the Artemio Franchi in the club’s Scudetto-winning 86-87 campaign, those Fiorentina fans stood in the Curva Fiesole instead believed this to be the latest example of the fear that Roncaglia induces in his fellow man.

Edi Cavani apparently wasn’t too scared. It was Roncaglia that he courageously challenged at the near post shortly before half-time, El Matador outmanoeuvring El Torito, the Little Bull, with a push forward and a step back to make the space for an equalising header, his 100th goal for Napoli, which earned a point for his team.

Standing on the sidelines in a club jacket and a purple polar neck, Fiorentina coach Vincenzo Montella wasn’t happy. Earlier in the week he had warned his defender—who, after being ever-present in his team for most of the season, had recently been left on the bench a few times—that he wasn’t “untouchable.”

And yet for Fiorentina supporters, he is exactly that. Because even if Roncaglia was beaten on a couple of occasions on Sunday lunchtime, he has never been beaten up. “Not yet, amigo,” he grins. If you come at Roncaglia, you better not miss. For this is the hardest man in Serie A and his reputation as such has brought him cult hero status at Fiorentina.

Not long after Roncaglia joined the club on a free transfer from Boca Juniors last summer, a Facebook page, which now counts more than 15,000 likes, was created. So too was an accompanying website called “When Facundo Roncaglia…” Essentially, his personality cult is defined by Chuck Norris-inspired facts and jokes. For instance, “When Facundo goes swimming with sharks, they’re the ones who need to go into a steel cage” or “When Facundo gets hungry, the fridge has to go out and do the shopping.”

The list of aphorisms has reached 499 and they are compiled among other things in a book, “Facundo Rulez”. Buy it and your money goes to charity. The title is a supposed statement of fact. However, within it’s pages there is actually a code of conduct to be followed if you are to become a member of an entirely fictional Facundo Roncaglia Fight Club. The first rule is NOT “Do not talk about Facundo Roncaglia Fight Club.” People clearly already are. Rather it’s: “Do not support Juventus.” The second rule, unsurprisingly, is also that you do not support Juventus.

It has become a phenomenon. “I honestly can’t explain it,” Roncaglia told La Gazzetta dello Sport. “When I play I always try to give my best. I’m not someone who goes out a lot but if I do, people recognise me, they hug me and pay me compliments, but I think it’s for what I do on the pitch over 90 minutes.”

The older ones in the crowd at the Artemio Franchi see in Roncaglia the second-coming of Daniel Passarella, El Gran Capitán of the Argentina side that won the World Cup in 1978 and 1986. He moved to Italy in 1982 and struck fear into the hearts of whom ever he faced while at Fiorentina and Inter. No one was safe.

Passarella once knocked out his own teammate Alessandro Altobelli in the dressing room at the Stadio Friuli after a game against Udinese. On being confronted with a knife in the showers by the still groggy Inter striker who’d only just come round, Passarella said: “Come on then,” while nonchalantly shampooing his hair. Other misdemeanours on his rap-sheet include head-butting an opposition physio and kicking a ball-boy for taking his time returning a ball.

“I never saw him play, not even on video” Roncaglia revealed to La Nazione, “but everyone is always talking to me about him. Having not seen him play I don’t know if I’m like him as a defender, maybe as a character.”

Asked if he has ever brought the game into disrepute with a professional foul, Roncaglia sheepishly told Gazzetta: “Uuuuuh… Many times… In the Copa Libertadores against Estudiantes: an elbow in the teeth. I really hit him hard.”

Like Passarella in his playing days, the threat he carries on the pitch isn’t limited to physical violence. Roncaglia scores too. Not to the same degree as Passarella, who found the net more than any other defender in Argentine football and struck on a remarkable 35 occasions during his time in Italy. But three goals this season are more than expected.

Or maybe not. Roncaglia the boy started out as a combative centre-forward in his hometown of Chajarí. “I played against Lionel Messi when I was 11. Even then you couldn’t ever get the ball off him.” A change of position was recommended, however, precisely because, as Catania’s Argentine whipper-snapper Alejandro Gomez says, “he’s a little guy like me, strong and fast, difficult [for smaller, trickier attackers like Messi] to get away from.”

It’s that, and his Italian passport and roots – the Roncaglia family can trace their origins to the Veneto and Campania regions as well as Florence – which has supposedly brought him to the attention of Italy coach Cesare Prandelli. “La Selección remains my priority because Argentina is my country,” Roncaglia said, “but if a call-up weren’t to arrive I’d like to play for Italy.”

Rather than the next Passarella, maybe Roncaglia could be the long lost heir of Claudio Gentile instead. Just thinking about it is enough to send chills running down the spine.