The odds of Rocky Fielding replicating Tyson Fury’s heroics when he steps into the ring at Madison Square Garden on Saturday night against Saúl “Canelo” Álvarez are certainly longer than were the Gypsy King’s against Deontay Wilder in Los Angeles last weekend.

But one man who is disregarding the 8-1 bookmakers have put on Fielding is Tony Bellew, the recently beaten and retired world champion who knows plenty about upsetting the odds. He said of his fellow Liverpudlian’s chances: “In a boxing ring anything can happen, absolutely anything. Let me just tell you, Rocky Fielding will not be as big an outsider as Buster Douglas was against Mike Tyson [42-1].”

He told the Liverpool Echo on Friday: “I’ll be honest with you, he’s up against it. It’s a massive task. If he can make his size and extra power advantage work for him, which I believe he can, then he definitely has a chance. Never write off a scouser.”

Nevertheless, it is asking a lot of the boxing gods to deliver two British fairytales against highly fancied fighters in the US in the space of a fortnight.

Fielding – who took the fight without even asking about the purse – has never lacked for self-belief, though. When his trainer, Jamie Moore, rang him late one night to tell him Eddie Hearn had delivered him the fight from heaven – or was it hell? – Fielding was in no doubt. He immediately tweeted: “Living the Dream … From Salford Sports Centre to Madison Sq Garden. Rocky from Stocky v Canelo. #LetsDoIt.”

In a conference call with media this week, he underlined his growing conviction that surpassing Fury’s draw with a victory is not as fanciful as many experts believe. “It’s a massive fight for me,” he agreed. “At Madison Square Garden, and a big challenge in Álvarez. But I’m going to put everything into it. I have sacrificed everything.”

He absolutely has more than a puncher's chance. Rocky's a very intelligent fighter, and he's underappreciated Jamie Moore, Rocky Fielding's trainer

Asked how he might get the better of a champion who gave Floyd Mayweather Jr a decent argument and who twice outpointed the estimable Gennady Golovkin – albeit controversially – he gave himself “a puncher’s chance”. But, he insisted: “I’m a good fighter, a good boxer.”

He is, after all, the WBA super‑middleweight champion, having knocked the stuffing out of the unbeaten title-holder, Tyron Zeuge, in the fifth round in Germany in July. And the only man to beat him is another Liverpudlian, Callum Smith, who caught him cold in the first round when they fought in late 2015.

Smith, who is still unbeaten, went on to stop George Groves in the seventh round in Jeddah in September, the dramatic conclusion to the World Boxing Super Series tournament at 12 stone, which also brought with it the WBA’s “super” version of this title. A domestic showdown with both belts on the line would be the sort of rematch the WBA and Hearn could only dream about – not to mention the fighters.

Fielding, who has operated below the radar for much of the time since losing to Smith, hurled himself back into centre stage shortly before his 30th birthday with his conclusive punishing of Zeuge, away from home in an environment that has rarely been kind to visiting contenders. While his power is not one-punch concussive, it is considerable, and the champion was rendered a limp target under the systematic pounding he took at the end.

Rocky Fielding during his win over David Brophy at the Echo Arena in his home city, Liverpool. Photograph: Andrew Couldridge/Action Images

Moore, one of the sport’s most astute mentors, challenged the earlier contention that Fielding’s only chance of beating Álvarez was through getting lucky with one punch. “He absolutely has more than a puncher’s chance,” the trainer said. “Rocky is much more of a rounded fighter than to just go in there and hope to land a lucky shot. He’s a very intelligent fighter, and he’s underappreciated.

“A lot of fighters – especially the ones he spars – say you don’t realise how good he is, or how unorthodox. We’ll find that out on the night of the fight. We’re going to ask [Álvarez] questions. And there are a lot of unanswered questions in him moving up to super-middleweight. Rocky has huge height and reach advantage. There’s a 10-pound weight limit the morning after the weigh-in, but the actual difference between them from that point until they get in the ring is going to be massive.”

That might not be so. Álvarez is a big middleweight, and he knows how to put weight on after coming off the scales. When Amir Khan moved up to challenge him for his WBC title in 2016, he claimed later, after being knocked out cold in the sixth round, that the Mexican outweighed him by nearly two stones.

Álvarez will start a prohibitive favourite, no question. His pedigree is way deeper than Fielding’s, with victories over Julio César Chávez Jr, Miguel Cotto, James Kirkland, Erislandy Lara and Shane Mosley – as well as a collection of British hopefuls: Matthew Hatton, who went the distance with him in 2011, Ryan Rhodes, who lasted into the 12th round three months later, and Khan.

Álvarez, who is having his 54th fight, is still only 28, having turned professional in 2005. He is as seasoned an opponent at elite level as there is in any division, a genuine great. For Fielding to beat him, Moore will have to devise a perfect fight plan. And whatever the insistence by the visiting camp that Fielding can bring unexpected skills to the occasion – much as Fury did against Wilder – there is an obvious gap in their history and achievements.

Fielding, three years older, began boxing for money five years after Álvarez started, coming to notice when he won Matchroom’s Prizefighter tournament in March 2011. That was the month Álvarez was giving Hatton a boxing lesson over 12 rounds in Anaheim, in defence of his WBC light‑middleweight title. Still, as Fury showed, reaching for the impossible is what boxing is all about.

Asked how he was handling the pressure, Fielding said: “I’m enjoying it. This is what I’m in boxing for. This is what I’ve been doing since I was nine years old. Where I’ve come from and my background, to fight at Madison Square Garden against the biggest name in boxing is unbelievable. I’m not letting it get to me. I’ve been fully focused on it these past 10 weeks. It’s a great thing.”

Fighters do not allow the prospect of defeat to crowd their thoughts but, if Fielding gives of his best and even inconveniences or hurts Álvarez, he will have scored a victory of sorts.