The Lionel Messi question: How will Pep Guardiola cope against his Barcelona protégé?

It was a subject that, of course, was always going to come up.

The only surprise was that Pep Guardiola was so willing to engage with it, and to discuss it, but he so clearly wanted to set the record straight.

Because, on the eve of his second return to Barcelona as an opposition manager, in his second job since leaving the club, he was naturally asked about reports he had tried to sign Leo Messi in the summer.

“I didn't call any player on the phone,” Guardiola stated. “I know there are wars that are lost before they are even started. I don't want to justify my words and compare them against what has been said. It would be nice if both versions of the story were contrasted. Nobody has called me.”

Guardiola went on to give a lengthy response about Messi’s place at Barcelona, and how anyone would want him if he ever decided to leave, but it’s difficult not to wonder how much of his response was also connected to a long-running discussion.

Despite Guardiola stating the obvious that everyone would want Messi, the question over whether he would want the Argentine is usually connected to the more loaded question over how much he actually needs the Argentine.

It remains the big debate about the Catalan’s career, and is always going to face renewed focus when he returns home, to face the main subject of that debate: just how responsible was Messi for Guardiola’s ground-breaking success at Barcelona?

By extension, it’s one of the main undercurrents to a match like Wednesday: can Guardiola get a team to anywhere near the same level without Messi? And can Guardiola solve the problem he used to give everyone else, and actually stop Messi?

The City manager’s last trip to Camp Nou seemed to crystallise so much of this, and almost served as a case study.

Back in April 2015, Bayern Munich were forced to face a rampant Barcelona side that were finally being talked of in the same vein as his 2010-11 side, and a Messi in his best form since that season. Guardiola tried to come up with something radical to stop it, first playing a startlingly high backline before changing, and it’s often forgotten those approaches made it quite a tight and tense game until as late as the 77th minute of the first leg.

It’s forgotten, however, because Messi just went and produced one of his most memorable ever performances to settle the tie there and then. In between beating Manuel Neuer on his near post and then setting up Neymar to put the tie out of sight, the Argentine also produced one of his most sensational goals – humiliating both the goalkeeper and Jerome Boateng in the one move, brilliantly putting both on the ground, the defender with a turn, Neuer with a deft turn.

It was, in short, the sort of thing no approach can legislate for.

Jose Mourinho actually admitted as much later that week, stating: “It is not about stopping him but giving him a difficult match. That is the best you do against him.

“People think in the wrong way. One thing is a team. Another thing is a team with Messi. It is a different story.”

A team with Messi in that kind of form can go on and win the treble, as Barca did for the second time in six years that season.

And this is the big thing with that debate. By now, it should be obvious to even the most ardent Guardiola deniers that he does so much more than just go to a club and let their best players play. He consciously seeks to maximise them, by enhancing their individual qualities within a collective system. The movement and interchanges he coaches are still of a higher sophistication than pretty much any other manager in the world, and are probably as unstoppable as Messi when on form – you only have to look at Bayern’s own landmark performance against City in 2013-14, or the utter destruction of Roma the following season.

That was the key with that Barca too. Guardiola completely maximised Messi, Andres Iniesta, Xavi and co. so that they were more than just a great team. They were arguably the greatest ever.

For all the talk about whether the 2015 vintage were better than them, too, they have been nowhere near as consistent or as much of a guarantee. This is a much looser team, ironically more dependent on their stars being on form, because they don’t have quite the same tactical identity under-pinning the side.

Guardiola’s Barca won two Champions Leagues, never once went out before the semi-finals, and there is a fair argument they would have completed the mythic three-in-a-row had it not been for a volcano. The point is that it may well have been the side closest to perfection there has ever been, but it also meant Guardiola made it unfair for all his future teams. He was unlikely to ever again get a set of circumstances like that, or a player like Messi.

Now he must once more try and think up the circumstances to stop Messi. The reality is probably as Mourinho suggested: you can only try and make it difficult for Messi. If he is on any kind of form, however, there’s not much you can do.

At the very least, Messi is not quite in the form he was facing when Bayern in 2015 and Barca don’t right now pose the threat they did that night.

The wonder is how Guardiola will react. What will he come up with? Will he seek to fully deny Barca and Messi the ball?

He will want to set the record straight, but this is far from a straight-forward question.