It's taken 15 games, but Pep Guardiola finally appears to have settled on his strongest Manchester City side. Without Kevin De Bruyne, at least. At Old Trafford, City outclassed Manchester United without reaching third gear. It's not a surprise that they did so with their best teamsheet of the season.

If anything, the form of City's new-look starting XI could even beg the question of where De Bruyne would fit in when he's back fit in the new year.

The reason it's taken so long for Guardiola to settle on his strongest side of the season is the return of John Stones, finally back from injury. Having been eased back in, and sitting out the Champions League win in the week, Stones partnered Ruben Dias for the first time of the campaign on Sunday in City's 15th game. There is no 'strongest starting XI' without Stones and Dias in the same lineup.

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Kyle Walker returned at right-back, and Josko Gvardiol was selected ahead of Nathan Ake on the left. Gvardiol appears to have overtaken Ake as first-choice at left-back - a theory supported by his selection at Old Trafford. Gvardiol is still raw in a position he rarely played before joining City, but is exciting going forward and has been solid enough defensively. He's adapted to City's inverted defenders system well, arguably providing more from the left than Ake does.

Rodri's importance was highlighted when City lost three from three without him recently, and no player did enough to show they can rival him for a start in big games. Mateo Kovacic, Matheus Nunes and Kalvin Phillips remain lower down in the pecking order, with Bernardo Silva a better option in midfield - as he showed with his masterclass at United.

In attack, Jack Grealish has struggled for games amid the emergence of the exciting Jeremy Doku, but nobody was surprised that Grealish started the derby. His big-game experience helped City win the Champions League last season, and he was integral to the derby demolition.

On the opposite flank, Phil Foden has impressed in central areas so far, yet his derby performance was a fine example of a right-winger who had the beating of his full-back throughout and stuck to the gameplan that involved stretching the makeshift United defence as wide as possible. It's a similar role that Bernardo played so well en route to the treble last season.

Erling Haaland is undroppable in attack, and Julian Alvarez has been a revelation in the number ten position so far this season. He has been quiet in the bigger games - at Arsenal and United - but seven goals and five assists at a rate of a goal involvement every 86 minutes justifies why he keeps getting selected.

Maybe Alvarez will be the unlucky player to get dropped when De Bruyne returns - but City have got Haaland involved more in the build-up thanks to Alvarez, so could Bernardo switch back to the right in place of Foden to get De Bruyne and Alvarez in the same side?

With the exciting options of Doku and Rico Lewis, and the solid defensive duo of Manu Akanji and Nathan Ake will keep the back line fresh. Nunes and Kovacic are good enough to give the other midfielders a rest when the fixtures keep coming.

With Chelsea, Liverpool, Tottenham and Aston Villa all coming up before Christmas, plus three important Champions League games to come, City will need a full squad - but also a settled strongest XI - just like last season when they won the treble. The side that beat United look like being the XI that Guardiola will trust until the new year at least.