In amongst all the bluster and braggadocio that makes up his autobiography – the tales of stealing bikes and driving cars at 325kmh, of falling asleep drunk in a bathtub after winning the title with Juventus and of kicking Antonio Cassano in the head after taking one with Milan – Zlatan Ibrahimovic does actually say one or two things that are rather revealing. In fact he says quite a few, talking candidly about his father’s problems with drink, for instance, and the way that his mother would hit him with wooden spoon until it snapped.

But the section that seems most pertinent ahead of a key Champions League game against Barcelona regards Ibrahimovic’s time at the Catalan club. Chances are you’ve already heard the top lines: the striker’s rants about how Pep Guardiola ignored him, about how the manager “drove him like a Fiat 500”, instead of the Ferrari he believed himself to be. The bit where Ibrahimovic tells his then boss “You have no balls” and “You shit yourself in front of Mourinho”.

Much of what is written in these passages is, as Graham Hunter wrote this week,nothing but sheer self-indulgence. Ibrahimovic rails at Guardiola for telling him what to drive – “here we don’t come to training in a Ferrari or Porsche” – for expecting him to run so much and for arranging the team’s formation around Lionel Messi. But every now and then he also cuts to the chase. “On the pitch I was still doing well,” notes Ibrahimovic at one point. “But I wasn’t enjoying myself.”

Objectivity is often hard to come by when discussing a player as divisive as Ibra, yet his assertion regarding on-pitch performance can certainly be backed by statistics. In 29 league games for Barcelona – six of which he started as a substitute – he scored 16 goals and created seven assists. In the Champions League he scored four in 10, and set up two more. His strikes included a winner against Real Madrid, a brace away to Arsenal and an equaliser his team had scarcely merited in Stuttgart.

Yet the fact Ibra was scoring goals is what makes his intimation that he was not having fun seem poignant. Any player might feel unhappy after getting off on the wrong foot with a new manager, but for a striker to no longer relish connecting ball with net is another thing entirely. Which raises the question: was Barcelona’s biggest mistake was identifying Ibrahimovic as such in the first place?

The Swede had arrived on the back of a season in which he struck 25 times in Serie A alone – enough to make him that year’s Capocannoniere – and was certainly sold to the Barcelona-supporting public as a great goalscorer, one whose height and power would give the team a new dimension. A classic target-man who could provide goals just as well as the departing Samuel Eto’o had, while also serving as the fixed point around which Barcelona’s constellation of talents would orbit.

Yet the reality is that goals might never have been an obsession for Ibrahimovic, as much as a means for making himself the centre of attention. The chance to drop back, to execute a clever assist or even just an outrageous flick can be just as effective in that regard. As he would tell Guardiola in one of the conversations that precipitated the collapse of their relationship, “if it was just a goalscorer you wanted you should have bought [Pippo] Inzaghi.”

At one point in the book he even recounts how Fabio Capello sat him down alone in front of a VHS showing every goal Marco Van Basten had ever scored, and within minutes he was contemplating whether he could get away with sneaking out (he eventually did).If scoring goals only held limited interest then watching others was positively dull. In the end Ibrahimovic’s greatest motivation for scoring was not internally driven at all, but stemmed largely from the desire to prove others’ wrong.

“My entire career has been built on a desire for revenge,” he notes at one point in the book, and his reaction to finally becoming Capocannoniere in 2009 illustrates the point. “When I arrived in Italy, people said I didn’t know how to score goals,” declared Ibrahimovic in the immediate aftermath of a 4-3 win over Atalanta on the last day of that season. “Now I have shown them.”

Two years on, now he has the opportunity to show Guardiola something. On top of their personal differences, Ibrahimovic protests at length in his book about the decision to move Messi – at the Argentinian’s request – back into the middle of the park. It was a change that he felt trapped him in a box, limiting his freedom of movement and ensuring that the team’s passes in that area of the pitch would be focused more towards the Argentinian. Ibra would be in position to score goals, sure, but not to express himself as he would wish.

Now at Milan, Ibrahimovic is once again the undisputed king of the castle – perhaps not totally unconstrained by tactics and formations but certainly free to interpret a game as he sees fit within Massimiliano Allegri’s 4-3-1-2. Increasingly, it seems Ibrahimovic’s instinct is to hang deep – spending less time in the area than sat outside it, looking for ways to release his team-mates inside it. At times against Fiorentina this weekend he looked less like a centre-forward than a trequartista.

That is in part a reflection of his growing realisation of the way his body is changing as it ages – another point he acknowledges in the book, saying that he has become a “weighty but explosive attacker who must play with a bit more guile in order to manage an entire match”. He is all too aware of the need to conserve energy in this part of the season in order to avoid a repeat of the February burn-out he suffered last time out.

But it is also perhaps another case of Ibrahimovic setting out for revenge, seeking to show Guardiola just what he missed out on by attempting to limit the player’s freedom. Tomorrow night at San Siro, he will have the opportunity to make his point in person.