MUCH of the build- up to yesterday’s Manchester derby focused, inevitably, on the eternal rivalry between Jose Mourinho and Pep Guardiola. The subplot was Zlatan Ibrahimovic v Guardiola. Fair enough.

Few though picked up on that other storyline, the photonegative of Zlatan v Pep: Kevin De Bruyne’s rocky relationship with Mourinho.

The Special One gave him two league starts and then dumped him for less than £20 million a few months later. Eighteen months on, he moved to City for more than three times the fee.

Yesterday, De Bruyne – along with Fernandinho and Nicolas Otamendi – was key to City’s first-half demolition of United. The way he moved from patient possession to direct, cutting edge – witness his opening goal – was breath-taking. He embodies why this City side are different from the old tiki-taka. That was primarily horizontal, oscillating until a weak spot was found. This possession is vertical, north-south, each pass carrying with it the threat of a sudden shot or, at least, acceleration on goal.

Mourinho’s recipe to counter this – Jesse Lingard and Henrikh Mkhitaryan on the wings – blew up in his face. The wide men simply got pushed back and, in transition, lacked the quality to hurt City.

“We started the game with some players who were really below their normal level in terms of concentration and aggression,” Mourinho said. Referring to the half-time changes, he didn’t mention Lingard and Mkhitaryan by name, but he said: “Some individuals did not give me what I wanted... Is it their fault? Is it my fault? It’s my fault because I’m the manager, it was my choice to play them.”

City scored twice but it could have been more. This is a team which, even with the suspended Sergio Aguero, tend to reap less than they sow.

United, on the other hand, could have been level. Claudio Bravo’s blunder allowed Ibrahimovic to pull one back. Another mis-hap gave the big Swede the chance to equalise deep in first-half injury time, but his limp finish was hooked away by the recovering John Stones.

Mourinho switched to a 4-3-3 at half time with the insertion of Marcus Rashford and Ander Herrera. Now they had the sort of midfield that could disrupt City’s possession and, for a while, it looked as if they might get back into the game. But then Guardiola himself stiffened the middle of the park – Fernando on for Kelechi Iheanacho – and at that point Mourinho ran out of answers.

United’s initial plan simply did not work and it rather confirmed what some had foreshadowed: a Marouane Fellaini-Paul Pogba midfield partnership is going to be problematic against opponents who keep the ball. Fellaini’s mobility is limited and if you shoehorn Pogba into a defensive midfield position, you are not getting your £100m worth.

Mourinho, to his credit, recognised this and it’s fair to say they won’t be facing City every week. But, more than the Rashford debate, it’s something that could define United’s next few months.

As for City, Bravo is an eyebrow raiser. When United began to press, it was almost as if the Chilean became the parody of a ball-playing keeper, almost as if – perhaps unconsciously, saying: “See? Joe Hart could never do this, could he?”

Some of it felt frankly superfluous and self-indulgent and the fact of the matter is that City gave up a goal and could have given up a second following Bravo errors. Not to mention a clash with Wayne Rooney early in the second half when both contested a loose ball. His studs were up and, had it been anywhere other than in the box, it would have been a foul. Which in this case would have meant a penalty and a red card.

It’s not a question of the quality of the keeper, it’s a question of the degree to which you ask him to do certain things. That should provide food for thought, as should the fact that, four games in, City have yet to keep a clean sheet in the Premier League.

Still, right now, it feels as if Guardiola’s crew are several notches above. And the scary thing is they are still learning the system and they did this without Aguero, Vincent Kompany, Ilkay Gundogan (though if Fernandinho keeps playing like this, you can’t see the German getting in there) and only a few minutes of Leroy Sane.

BARCELONA may have started the season well, but they did not quite pick up where they left off, did they?

Ahead of Alaves visiting the Camp Nou yesterday, Barcelona had won four out of four compet-itive games this season, scoring 12 and conceding two. Contrast this with how they ended last year when they won their last six, scored 24 and conceded none. Same rate of victory, but goals scored are down and goals conceded are up.

It’s an absurdist argument, of course. But it does underscore the current state of Luis Enrique’s team that some in Spain are fretting over those comparisons. Neymar has yet to play a minute, with Andres Iniesta recovering from a knee injury and Marc-Andre ter Stegen in the sick bay, and they still worry about the fact they are averaging “only” three goals a game against opponents of the calibre of Sevilla and Athletic Bilbao.

If there is a change relative to last season it’s that the squad is deeper. Arda Turan is now settled and effective and Rafinha has returned from injury. In the transfer window, they spent big on newcomers who might not crack the starting XI, but provide alternatives in every role: Jasper Cillessen in goal, Samuel Umtiti and Lucas Digne at the back, Andre Gomes and Denis Suarez in midfield and Paco Alcacer up front. Sergi Roberto is also helping folks forget about the departed Dani Alves.

What this points to is perhaps a more judicious use of the prize assets, keeping them fresh for bigger games, especially the ones with transatlantic international commitments. If Luis Enrique can make it work, this group will be head and shoulders above the rest of the European pack.