Sheffield United: Mark Duffy, King Kenny and a stroke of genius from Alan Knill

But the story of how he followed in the Liverpool legend’s footsteps, becoming a trequartista rather than a touchline hugger, is surprising. Particularly, Duffy explains, because it begins on a muddy training pitch somewhere in deepest Lincolnshire.

“I used to be an out and out winger. Trying to beat my man down there. But everything changed when I was at Scunthorpe. Knilly took me to one side and told me, when they couldn’t get the ball wide, it was like being a man down. So he dragged me inside, worked on my positioning, and everything went from there.”

‘Knilly’, otherwise known as Alan Knill, is now Sheffield United’s assistant manager having left Glanford Park five years ago. When Duffy arrived at Bramall Lane during the close season, becoming the club’s first new signing of the Chris Wilder era, it enabled him to resurrect the most influential partnership of his sporting career.

“I’ve got so much to thank Alan for because he’s really developed me as a player,” Duffy continues. “He thought I had the ability to play a different role and showed that faith in me. Even more important was the time he spent trying to perfect what I was doing because, when I first started there, I probably did lots of things wrong. But Alan showed lots of patience and came up with some really good ideas. Like I said, I really can’t praise him enough.”

Knill and Duffy is a marriage made in heaven because both, the latter admits, are fervid students of the game. Knill’s home, in Sheffield’s south eastern suburbs, is stuffed to the gills with diagrams of the set-piece routines he takes pride in devising. Duffy, responsible for setting many of those in motion, uses his spare time to study archive footage of opponents, greats like Dalglish and new footballing trends.

“It’s something I enjoy, the thinking side. I think about my position and where the space is. Sometimes, I’ll play like a ‘10’ but really I’m an inside winger, getting into pockets off the overloads. You can find space everywhere and I enjoy searching it out, trying to anticipate where it will come up and making sure I get their first.”

Duffy, aged 31, spent two-and-half seasons with Scunthorpe after leaving Morecambe midway through the 2010/11 campaign. Thirty months and over 100 appearances later, he joined Doncaster Rovers before heading to Birmingham City where, having spent last term on loan with Burton Albion, he helped deliver Championship football to the Pirelli Stadium. But when his contract at St Andrews expired, the opportunity to work with Wilder and Knill proved impossible to resist. Especially, Duffy explains, because he admires people who are obsessed by small details.

“The game has developed so much so you do have to adapt your game. You have to identify where the space is and sometimes, yes, it is out wide. The gaffer and the staff work hard on that with the front lads here. They always make sure one of us is pulling, the other is pushing and the other is in the ‘hole’ as it were.”

“The bodies on the pitch is the big difference for me now, playing as I do,” he adds. “You have to know what’s going on around you and be a lot more aware. I used to just play on the shoulder of the full-back and try and beat him there. But when I came inside, you’ve got to know what’s going on more. It causes the full-back a problem too because he doesn’t know whether to follow you or not. Little things like that, I really enjoy working on.”

Of course, a fascination with the nuances of the game are not the only reason why United enter tomorrow’s match against Rochdale unbeaten in five and seven points clear at the top of League One. Wilder, who led Northampton Town to promotion last season, admits he embraces many scientific methods. But, having cut his coaching teeth with Alfreton and Halifax, has combined them successfully with the more social aspects still prevalent in the semi-professional and non-league game. Duffy, who represented Vauxhall Motors and Prescot Cables before heading to Christie Park via Southport, thinks it is a potent mix.

“We work hard but we also enjoy ourselves. There’s a real honesty among the lads here, no egos at all.

“When people make mistakes, they always come in and apologise. But the lads get around them and say ‘it’s not down to you, it’s all of us.’ It’s a really strong squad like that. Nobody hides away from anything and stuff doesn’t eat away at people because that frankness is there.”

So to, with over three thousand supporters travelling to Spotland, are the crowds.

“It’s unbelievable when you go out in that,” Duffy says. “It begins through the week, with Billy (Sharp) coming in saying there are going to be 26,000 plus here if we’re at home, and carries on from there. It’s a nightmare getting tickets when Billy is handing them out and then there’s the gaffer wanting his 15, out of the players’ allocation by the way. You feel it when you come out for the warm-up and then, home or away, you can almost feel the fans trying to suck the ball in. Seriously.”