Guardiola, of course, made his name at Barcelona by creating one of the best football sides in history, sticking to Barca's classic footballing beliefs: width, 4-3-3 and possession play. His stint at Bayern was different, demonstrating a more flexible nature to Guardiola's coaching. He didn't rigidly adhere to his Barcelona principles, and instead adapted his approach to suit Bayern Munich's stars, becoming increasingly experimental with his formations.

The big question for Guardiola at Manchester City, therefore, would be how he found the balance between introducing Guardiola-style football and continuing with City's existing footballing identity.

Guardiola introduced his typical principles almost instantly: there was a sweeper-keeper, ball-playing centre-backs, inverted full-backs and an overwhelmingly creative midfield trio.

Slowly but surely, however, Guardiola has abandoned his intended approach for Manchester City and increasingly reverted to the system they played under Manuel Pellegrini. There are four distinct examples:

1. Goalkeeper

Changing City's No. 1 was Guardiola's most obvious "changing of the guard" moment. Joe Hart had endured a few difficult campaigns, but other managers might have hoped a new coaching regime would rejuvenate his career.

Claudio Bravo OLI SCARFF/AFP/Getty Images

Not Guardiola, however. Among question marks about his ability to play as a sweeper-keeper, Hart was unceremoniously dumped, and Claudio Bravo was introduced as his replacement. On his debut against Manchester United, Bravo provided a remarkably exaggerated example of a sweeper-keeper performance, positioning himself permanently outside his penalty box and continually playing the ball out when pressured by opposition players. He made a mistake for United's goal, dropping a cross to Zlatan Ibrahimovic, and was twice caught in possession too. But this is what Guardiola wanted.

Since then, however, it's become clear that Bravo isn't a particularly good goalkeeper in a traditional sense. At one point, he conceded six consecutive shots on target, but perhaps more significantly, he essentially abandoned his sweeper-keeper style, positioning himself traditionally. Meanwhile, his performances became so bad that he was on the bench between Jan. 21 and April 8, with reserve goalkeeper Willy Caballero preferred. Bravo has regained his place, but with his confidence dented by mistakes and being dropped, he now simply seems like a dodgy goalkeeper rather than a progressive sweeper-keeper.

2. Full-backs

At Bayern, Guardiola had stunned opponents by often asking his full-backs to play a very peculiar role; rather than overlapping down the flanks, they were asked to drift inside to midfield positions. Philipp Lahm and David Alaba were both comfortable in central midfield, so the move worked effectively, guarding against opposition counter-attacks and allowing Bayern's wingers space down the flanks.

Guardiola tried something similar at City, with Bacary Sagna and Gael Clichy asked to do something similar during the opening game of the campaign against Sunderland and in a couple of other early-season games. In truth, the experiment was less successful, primarily because these players lacked the technical quality and footballing intelligence of the Bayern pair. But it was nevertheless a progressive and interesting tactical move, the type of thing we'd come to expect from Guardiola.

There has been little sign, however, of this in recent weeks. Pablo Zabaleta has played this role on occasion, and there was a brief spell when Fernandinho did the same on the right. The Brazilian seems the most suited to that position among City's squad but is clearly required elsewhere.

Instead, Guardiola is now back with Clichy and Zabaleta or Sagna playing traditional old-school full-back roles.

Pep Guardiola Ian MacNicol/Getty Images

3. Ball-playing centre-backs

John Stones seemed Guardiola's pet project: a young, intelligent, technically gifted centre-back who needed to be taught how to defend. This was perfect; Stones would help define City's possession play, and Guardiola would mould him into a commanding centre-back in the same way he transformed Jerome Boateng.

But Stones has endured an underwhelming campaign, and his traditional defensive skills remain questionable. And while his possession play is occasionally impressive, he does make an extraordinary number of errors for a defender at a top club, not simply when attempting to play the ball out -- he also conceded a needless goal at Everton when trying to hack the ball into the stands. So far, it's difficult to see a significant improvement.

Guardiola started the campaign often playing Aleksandar Kolarov as the left-sided centre-back, a peculiar decision considering the Serbian often seemed too attacking for a left-back role, never mind a centre-back role. Nevertheless, that was precisely what we expected when Guardiola touched down in Manchester.

But again, this experiment has largely been abandoned, and Guardiola has essentially returned to using traditional centre-backs like Nicolas Otamendi and Vincent Kompany -- in part due to Stones' recent weeks.

4. Central midfield

Guardiola's early central-midfield zone was a thing of beauty: Fernandinho, Kevin de Bruyne, David Silva, in a 4-3-3 formation. Fernandinho sat deep and sometimes dropped into the defence, while De Bruyne and Silva drove forward from deep. It was overwhelmingly technical and incredibly brave, using a mobile box-to-box midfielder in the holding role and two natural Nos. 10 as Nos. 8.

On occasion it was simply tremendous. City travelled to Steaua Bucharest for their Champions League qualifier in August and demonstrated football from another planet: Silva and De Bruyne driving through midfield, swapping passes and racing forward to create chances. It was fast, technical, dynamic and unlike any other system you'll see in Europe this year.

David Silva and Kevin De Bruyne celebrate after scoring a goal against Borussia Monchengladbach. Matthew Ashton - AMA/Getty Images

But among disappointing domestic results Guardiola has gradually lost faith with that system. He's switched to 4-2-3-1, sometimes using De Bruyne out wide and regularly played Fernandinho alongside Yaya Toure -- a player Guardiola had previously banished from the squad. Again, it seems like a regressive move, and while Ilkay Gundogan's injury has been a significant setback, the loss of one injury-prone player shouldn't derail an entire approach.

The result of all this is simple: City now look very different from the defence and midfield that played under Manuel Pellegrini last season.

On the opening day of this season, Guardiola uses Stones and Kolarov as ball-playing defenders, Sagna and Clichy drifting inside from full-back, and Fernandinho just behind De Bruyne and Silva. Pellegrini wouldn't have done any of these things.

Yet for the recent 0-0 draw with Manchester United, Guardiola used a simple four-man defence of Zabaleta, Kompany, Otamendi and Kolarov, all players who played those roles under Pellegrini. Similarly, the Fernandinho-Toure combination was Pellegrini's first-choice formation. In goal, meanwhile, Bravo has returned to the starting XI but isn't playing anything like a sweeper-keeper anymore.

It's not all disastrous. Silva is enjoying another sparkling campaign, Raheem Sterling and Leroy Sane have been sporadically brilliant and should progress further, while Sergio Aguero has banged in the goals and Gabriel Jesus is a ready-made replacement.

But have City progressed? In pure points terms, City will collect more than last season. But, of course, the standard at the top of the Premier League has increased significantly overall. Intriguingly, City finished on 66 points last season, and champions Leicester collected 81. As things stand, coincidentally, City are on 66 points and league leaders Chelsea are on 81; in other words, City are essentially the same distance behind the pacesetters.

But again, it's not all about points; it's about style, and City don't feel significantly different from the Pellegrini side of last season. Rather than City adapting to Guardiola's new approach, Guardiola has adapted rather too much to City's old approach. This might be a transition season, but it rather feels like the transition has happened in reverse.