Of the many changes to have taken place at Barcelona under Luis Enrique, perhaps the most notable is their transformation from one of the most ideologically rigid and aggressive pressing units around into a more flexible team, capable of playing in different ways against different opponents.

Under Pep Guardiola, Tito Vilanova and, to a slightly lesser extent, Tata Martino, Barça tried to squeeze the life out of the opposition in every game, applying pressure all over the pitch and winning the ball close to the goal they were attacking. Now there are games in which certain players press, though not with the ferocity of old, and games in which the side plays a more conservative strategy, at times looking like an old-school broken team.

Given that Guardiola-era Barça dominated possession like few other teams in history, the players' defensive statistics were remarkable: in the 2009-10 La Liga season, Lionel Messi made 0.9 tackles per game and 1.2 interceptions; Pedro made 1.2 tackles and 1.2 interceptions; Xavi Hernández made 1.2 tackles and 1.4 interceptions; Andrés Iniesta made 1.5 tackles and 1.2 interceptions (all stats courtesy of WhoScored.com). These were figures as good as or better than those posted by players whose teams had the ball much less.

The beauty of tiki-taka got the headlines, but it was the pressing that made it work. The key to having the ball all the time was not just being able to keep it from the other team, but knowing how to win it back as soon as it was lost. Guardiola and Vilanova would not compromise on that: if you couldn't press, you didn't play. Languid attackers like Thierry Henry and Zlatan Ibrahimović lost their places to much less-heralded players who would do the hard running that they either could not or would not.

The biggest and most important change since those days has not been on the pitch, but in the boardroom. As soon as Sandro Rosell became President in June 2010, it was going to be harder to justify the exclusion of global stars like Henry and Ibrahimović. As one of the world's biggest clubs, Rosell believed, Barça simply had to buy these players: if not because they were needed, then to prevent them from signing for Real Madrid and making Barça seem inferior.

Consequently, the coherent tactical philosophy of the Guardiola-and-Vilanova era has been abandoned. Neymar and Luis Suárez have arrived and they have had to be accommodated. The manager can't tell the board that he has a way of playing and these guys just don't fit in, as Guardiola did. Faced with that line of argument now, the board would simply tell the manager to change his way of playing. If these players can't press, the manager is told, then the team doesn't press.

These are the conditions Luis Enrique is working under and he is adapting his tactics to help the players succeed in spite of what his superiors tell him. It makes sense therefore that his Barça doesn't have a uniform plan. Sometimes they look to win the ball high up the pitch and sometimes they wait for the opposition to bring it to them.

More often than not, the back four stays in a line and drops off fairly quickly to cover long passes over the top. The midfield trio tends to cover the central area in front of the defence and support the full-backs, while the forwards apply a burst of pressure to the opposition defenders but do virtually nothing if the opposition plays through that initial wave.

At both ends of the pitch, there's less automation and more improvisation. While having only the vaguest instructions suits Messi, Neymar and Suárez, it doesn't really help defenders who depend on mutual understanding and routine to get through games. A few times this season, particularly in matches against Málaga, PSG and Almería, Barça have struggled to clear their lines and have ended up boxed in by their opponents.

Playing without an organised pressing system inevitably means that raw defensive output falls. The interception figures suffer in particular - when there's no-one forcing the player with the ball to rush his pass, he's much less likely to play an inaccurate one. In this La Liga season, Messi has made 0.8 tackles per game and 0.1 interceptions; Pedro has made 0.6 tackles and 0.1 interceptions; Xavi has made 0.4 tackles and 0.6 interceptions; Iniesta has made 1.3 tackles and 0.4 interceptions (again, all stats are from WhoScored.com).

Of course, many of those players aren’t nailed on starters any more, but their replacements – Neymar and Suárez for Pedro, Ivan Rakitić for Xavi and Rafinha for Iniesta – are all posting similar figures. The stats confirm what the eye sees: that Barça aren’t pressing anywhere near as aggressively as they used to.

Inevitably, this has led to problems relating to Barça’s dwindling control over the midfield zone. Many culés are demanding a return to the old system, or at least requesting the re-introduction of some kind of concerted defensive action from the forwards that prevents Barça’s opponents from getting deep into their half before facing a challenge.

The sad truth is that a return to the old system is impossible. If the directors are determined on replicating the Zidanes y Pavones model, then the manager can't devise and implement tactics that exclude the Zidanes. Even if it was feasible, there are two big problems that should stop Luis Enrique going back regardless.

The first is that it’s much harder than it looks to build and execute a pressing system properly. It requires a lot of practice and co-ordination on the training pitch and also a great deal of familiarity between the players. While Luis Enrique is set on rotating players on a game-by-game basis, it’s next to impossible for them to get to know each other’s actions and execute such a complicated system effectively.

The second is that pressing all game, every game is extremely draining, both physically and mentally. As we saw in each of the last three seasons, the starting eleven usually ends up exhausted by February, rendering the pressing system impotent and leaving centre-backs helplessly stranded on the halfway line while opposition forwards sprint past them over and again.

These two facts, along with Rosell's desire to be Barça's Florentino Pérez, led to the scaling back of Barça’s ideological commitment to pressing.

In the long-term, we’re probably going to see more of the same: a match-by-match approach in which the forwards sometimes press, but just as often stand off; in which the defence sometimes plays high, but just as often sits deep; in which Barça sometimes look to dominate a match from start to finish, but just as often look to have periods where they play on the counter.

This goes against everything club icons like Johan Cruyff and Pep Guardiola believe in, but contemporary elite-level football doesn't allow for such ideological rigidity. Almost all of the biggest clubs are run by money-men like Rosell, who stock their squads with famous names and let the manager figure out how best to fit them all together. All the manager can do is try to be practical - and that's what Luis Enrique is doing now.