When Barcelona named Pep Guardiola as their manager, I said to myself: ‘Madre mía, we’re going to be flying; this is going to rocket.’ I knew him already, knew what he was like. He’s pesado: heavy-going, insistent, hard work, intense. He’s a perfectionist. He’s obsessive; I knew he would keep going until he got it right. If Pep decided to be a musician, he would be a good musician. If he wanted to be a psychologist, he would be a good psychologist. Football is his passion.

Guardiola is meticulous, focused on every little detail. Even as a player he controlled everything; he knew exactly what he wanted to do, he had it all laid out in his mind. He loves football and a particular way of playing it. He really hated losing the ball, even as a player. Those of us who have been raised at Barcelona, with the ideals that Johan Cruyff brought to the club, have a very clear sense of how to play, an ideal. Pep especially. He is a purist, a radical.

It is not enough just to have those ideals: you have to be able to communicate them too. There may be other coaches who share similar beliefs but are weaker and can’t transmit them. Guardiola can. He has the leadership, the personality. We needed that when he took over. He makes huge demands of himself and that’s contagious – it spreads to everyone. He has a vision and knows how to transmit that. His message reaches players. Just by being Pep, people listened to him at Barcelona. It’s a bit like Zinedine Zidane at Real Madrid: he has been everything in football, he commands respect because of who he is. That respect can only have grown. If Pep is not the best coach in the world, he is certainly one of them.

I have never worked with Carlo Ancelotti, for example, or José Mourinho but Guardiola and Luis Aragonés are the managers who had the greatest impact on me without doubt. His approach is applicable outside Barcelona; Munich was the proof of that. His team played very good football, the way he wanted to play. It’s true they didn’t win the Champions League, because small details did not go their way, but they kept on winning and he left his mark. Talk to the players there and they will tell you. I know Javi Martínez and Thiago, and I have heard others talk about him. They all say he is different to all the rest.

You really learn with Pep. He explains things very well: not just what you’re doing but why you do it. He is good at synthesising information. He talked about locking himself away in his office watching endless videos to prepare games until he found the key to it all. He might have spent two or three hours, or more, on a video but when it came to showing it to the players, it wouldn’t last more than 10 minutes. He doesn’t weigh you down with it. He’s heavy-going in the demands but not in the amount of information he gives you. The videos would focus on aspects of the games, precise details. We didn’t change our approach as such, it was more that he analyses how you can attack your opponents. They would reveal where the space can be found – behind the defensive pivot, for example – and explain how we can open that up. It’s all about time and space. He would look for those details to improve the team’s chances of conserving possession, creating chances.

Those ideas would then be taken on to the training pitch. You would walk through the movements he wanted but it wouldn’t be repeated over and over, a long session going on for hours. The sessions would be an hour and a quarter usually. In a sense, it was a mental exercise – thinking, understanding what you were trying to do. And then the final team talk would be a short summary of everything we had prepared. It would be tactical and technical but there would be an emotional, psychological component too.

When you are very clear in your ideas, when you know how to transmit them, it is easier. If anyone can change Manchester City, it is him. Besides, if you had asked me 10 years ago, maybe I would have said: ‘Bloody hell, it’s difficult,’ but English football has evolved, it’s not so direct and he won’t have to change everything at City. Manuel Pellegrini was there, Ferran Soriano and Txiki Begiristain are there.

The idea is similar to his and goes back a while now, which will make it easier. They had a style where they wanted to carry the game to the opposition, to have the ball, to be protagonists. Barcelona kept a clear identity and there’s an element of that at City. David Silva, Kevin De Bruyne, Sergio Agüero and Yaya Touré are all players who could have played for Barcelona and he will sign players that fit. And Guardiola can turn the screw on that, tighten everything up.

He won’t have problems with players that don’t fit. He’s very direct, very straight with people. They will know if they don’t train well, they won’t play. He will have no problem leaving out a star or putting a young player in. He did that with Pedro and Sergio Busquets, who had played only third division football until then and became regular starters.

He has matured and he has the experience from Bayern. He evolves too; he learns, he’s always looking to advance, seeking new solutions. There were tactical shifts there. Bringing the full-backs inside to open a pass to the wingers, for example. We hadn’t done that before at Barcelona. Intelligence is often expressed in terms of how you adapt and Pep is very intelligent. He would adapt to any football anywhere and be successful anywhere, I’m sure of that.

Those are shifts within the ideal, not a new philosophy. Pep once said if he could play with 11 midfielders he would, if he could have 100% of the ball he would do that too. So, he might change … he might become even more radical. If you believe in something, you have to follow it. For those of us brought up on those ideas, who have internalised them so deeply, it’s like a religion. Pep is a purist. And why change when it’s been so successful? I don’t think he will change his idea; I think he will try to perfect it.

Xavi Hernández played for Pep Guardiola at Barcelona from 2008 to 2012, during which time they won two Champions Leagues and three La Liga titles