"I don't know." It is the honest answer to the inevitable question for Arrigo Sacchi, the one he might have been asked 1,000 times since May 2009 – when Pep Guardiola's Barcelona confirmed their arrival as Europe's predominant force by swatting aside Manchester United in the Champions League final.

Sacchi's Milan, the last team to win the European Cup in consecutive years, had previously been held up as the benchmark of footballing excellence – the 1989-90 vintage named as the best club side of all-time by World Soccer in 2006. But could even they have stopped Lionel Messi and company?

"What I would say is that, thanks to teams like Ajax, Milan and now Barcelona, football is a sport which has evolved and consequently it remains compelling," says Sacchi, stalling, but behind the trademark, aviator-style, reading glasses his mischievous eyes betray him. Sacchi is too modest a man to be drawn into bold claims but he is also too proud to let his teams be talked down. The suggestion that his old-fashioned 4-4-2 might prove too rigid against Guardiola's more flexible schemes draws a more pointed response.

"No. It is not a question of 4-4-2 or 4-2-1-3, it is a question of having a team which is ordered, in which the players are connected to one another, which moves together, as if it was a single player," he interjects even as the question is being asked. "Today few teams know how to do this. Few teams work as a unit – few, really few teams. They are all made up of little groups. There is no great connection, nor a good distribution of players around the pitch.

"Barcelona has this. You saw it against Manchester United [in this year's Champions League final], this was the big difference between the teams. One was very much a unit, all 11 players were moving as if they were one. The other was moving as individuals who happened to be in proximity to one another. That Milan team was a team who moved well, with the players very closely linked to each other. It would have been a great game against Barcelona, between two great teams."

Despite his initial reticence, it is clear that it is also a hypothetical match-up on which Sacchi has mused before. He insists that no special ruse would be necessary to restrict Messi ("We dealt with Diego Maradona") and that his compact formations – in which the gap between the defensive line and the attack was often 25 metres or less – would not necessarily be undermined by modern interpretations of the offside law (a subject discussed in Jonathan Wilson's recent fantasy match-up between the two sides). "You just need players who know how to read the game," he says.

Indeed, to witness the enthusiasm with which the 65-year-old discusses the game it is easy to be drawn into wondering whether he ought not still to be out there, putting his theories to the test. He thumps his fist into the table as he lays out his vision of how the game should be played, espousing total football concepts of a team who attack and defend as one. "You see defenders today who follow an opponent everywhere," he protests in one of his more heartfelt monologues. "The defender's point of reference should never be his opponent but a team-mate."

Yet it is not by chance that Sacchi has been out of management since 2001. For starters, and despite his belief in the value of the team over the individual, he would never again achieve similar success after leaving behind a Milan team who featured Marco van Basten, Ruud Gullit, Paolo Maldini and Frank Rijkaard. Although he took Italy to a World Cup final in 1994, their performances failed to capture the imagination and the sceptics argued that only Roberto Baggio's genius had carried them so far. Euro 1996 proved disastrous and stints back at Milan and Atlético Madrid went little better.

More importantly, though, his body could simply no longer stand the strains of being a manager. Sacchi's final managerial appointment, at Parma, lasted 23 days before he was forced to move upstairs on account of stress-related illness. The same passion that has him hitting the table eventually proved overwhelming as a full-time tactician.

Instead, after several years as a director at Parma then Real Madrid, he moved into television and radio punditry. Then, in August, a new opportunity arose. Following Italy's inglorious group stage exit from the World Cup the Italian Football Federation had identified a need for complete reform of the national set-up. Sacchi was invited to oversee an overhaul of the youth sector, while his former Italy player Baggio was given similar responsibility for reinvigorating the famous coaching school at Coverciano.

What Sacchi found in Italy's youth teams disgusted him. "I see kids who are 14 or 15 years old who are already specialists. But football is not a sport of specialists," he says. "I was watching the under-15s the other day – 14-year-old boys – and the central defenders arrived and all they did was mark their man. They took themselves out of the game. This is suffering, this is not joy, this is not football. If someone does just one thing over and over, they will get better at that thing. But is football just one thing?"

But while he is anxious to change such a culture it will, by his own admission, take time. Sacchi's aim is to recreate a model for the national team along the lines of Barcelona, where every age group is taught using the same tactical approach and the same fundamental ideas about how the game should be played. "When I arrived every coach was just doing what he wanted," he says. "These kids were not getting continuity in their teaching."

But to achieve such goals a new generation of coaches is required and it is here that Sacchi's most radical and most strongly held beliefs come to the fore. Having never gone higher than the amateur ranks as a player, Sacchi believes fiercely that it is time football opened itself up to the idea of more non-footballers becoming coaches, citing the examples of José Mourinho and Zdenek Zeman as supporting evidence. As he famously put it when questioned during his own coaching career: "I never realised that to become a jockey you needed to be a horse first."

Sacchi had been able to enrol at Coverciano after five years working with the Cesena youth team but in Italy even roles such as that one are often inaccessible to people from outside the game. "In Italy they have still not opened up the registrations," says Sacchi. "I would let everyone – from pharmacists to porters – any person – become a manager. This way, in my opinion, we will end the domination of a single way of thinking. Instead we will have a thousand different ways of thinking. The more thoughts you have, the more you can grow."

And Sacchi certainly believes that Italy have a lot of growing left to do. Cesare Prandelli's success in steering the national team through the Euro 2012 qualifiers without a single defeat prompted triumphant headlines heralding a nation's footballing revival but Sacchi is more circumspect. Real gains must come from the base, not from a handful of good results achieved by a select few. There is a tendency among observers to react only to what is happening right at this moment, to "sail by sight", rather than looking further ahead.

"When you build a skyscraper, you make really strong foundations – if you don't make the foundations you will never see the skyscraper," he says. "If you build a shed, you don't need those foundations but it will never be an important building. Prandelli is doing a great job in difficult circumstances. But in the end the national team is only ever the last beneficiary of whatever work has been done at the outset. If something starts badly, it will not end well."

The same could be said of club football in Serie A, where the need to produce immediate results has led to a suspicion of youth. "When teams lose two games they sack the manager," says Sacchi, noting how fans will even go so far as intimidating the directors in order to affect a change of coach. "There is a great tension, a great pressure from the press but even more from the fans, a great violence."

Despite efforts to clamp down on such behaviour, it does persist. Just last season a group of Cesena Ultras vandalised a club shop where the wife of the owner, Igor Campedelli, worked, threatening to come back and do much worse if he did not fire the manager, Massimo Ficcadenti.

Campedelli, no shrinking violet, responded in kind, warning that, if anything similar happened again, he would "sell the team's best players and not register the team with the league [for the next season]". But others have proved less bold in the face of such anger.

Sacchi's hope is that Uefa's plans for financial fair play may provide at least part of the solution – forcing clubs to employ a more rational, finances-led assessment of a situation. "It is clear that debts take away calmness, planning and serenity from the clubs. And so the only things that will grow are violence, arrogance and hysterical reactions. I also hope it may get rid of all of those people who involve themselves in football not because they love the game but for other ends and who bring with them only arrogance, ignorance and incompetence."

Sadly one suspects that last hope may be a wish too far. Then again, before someone came up with the right foundations, even that skyscraper seemed like an impossibility.