THE verdicts are delivered without fuss.

This will Pep Guardiola’s toughest challenge. It may take him three seasons to achieve what he wants at Manchester City. Guardiola will have to change what made him successful at Barcelona and Bayern Munich. And the Manchester City players will be sentenced to a period of unrelenting hard labour.

The judgments have been made by someone who has watched Guardiola on the training ground, has been privy to both the coach’s methods and his secrets and has earned the respect of the Catalan. Marti Perarnau spent a season with extraordinary access at Bayern Munich. He was allowed on to the training field, into the gyms and dressing rooms and into the players’ restaurant.

He listened and watched as Guardiola took his brand of Barcelona brilliance and adapted it for the German model.

Perarnau chronicled all this in the extraordinary Pep Confidential and that year in Bavaria and his exposure to Guardiola gives him an unparalleled insight on what English football and Manchester City can expect from the most driven, insular, singular coach of his era.

Perarnau brings a sporting perspective to his writing. He qualified in the high jump for the 1980 Olympics but then became a journalist, helping the organising committee of the 1982 Olympic Games in his home city of Barcelona. He now works in television advertising though continues to write books.

His first book was on the Barcelona training academy where he first met Guardiola. The second was the revolutionary Pep Confidential that saw Perarnau patrolling the playing field alongside the coach and such as Philipp Lahm, Manuel Neuer, Franck Ribery and Arjen Robben. He was allowed, in a writing sense, a free role. He revelled in it.

Was he surprised Guardiola made no severe restrictions?

“Very surprised,” says Perarnau. “I got on well with Manuel Estiarte [Guardiola assistant] because we were both Olympians in 1980 and we were friends, but I didn’t expect such generosity from both Estiarte and Pep. The arrangement with Pep was simple: he let me see everything and I could write anything.” There was a minor restriction on revealing line-ups and potential signings before matches were played or deals were made.

“It was a perfectly reasonable arrangement and both parties stuck to it 100 per cent. Pep was so scrupulous that when I offered him the chance to read the draft of the book before it went to print, he turned it down. He said I was free to write what I pleased.”

Perarnau was thus granted an unprecedented insight into what drives and sustains one of the most successful and intriguing coaches.

“It’s very likely that Pep is a genius, but I can’t define the qualities that make a genius,” says Perarnau. “What I have seen in these years of being around him is that he is a tireless worker, he obsesses over details, he is passionate about football, he is a specialist of general strategy techniques and football tactics, he is a good friend of most of his players and he is a great analyst of opponent teams.

“Is that what you call a genius? I don’t know. If I had to define Pep the manager, I would say he is extremely passionate, a hard-worker and emotional.”

Guardiola graduated as a player at Barcelona to a manager who won 14 trophies for the club, including three La Ligas, two Champions Leagues and a couple of world championships. He left the club in 2012, enjoyed a year’s sabbatical and then joined Bayern Munich where he won three successive Bundesliga titles. At 45, he now comes to Manchester City on a wave of expectation, facing a storm of adulation or criticism whatever way his tenure develops.

Perarnau believes the Catalan’s decision to head to England was straightforward. “He wants to get to know another footballing world. It’s the same reason he left Barcelona and the same reason he went to Germany. It’s the same reason why he will leave Manchester to go somewhere else,” he says.

“Pep is a very inquisitive man. He is hungry for knowledge. He wants to experience different things, different cultures, different feelings. As for Britain, he is attracted to the land of the founders of football and eager to compete in a game that is so different to the Spanish or German one.”

And what can the Manchester City players expect? “I have one piece of advice for them: don’t save on mental or physical energy,” he says. “Pep will work towards making them a better team and, above all, work towards making every player a better player. He doesn’t have a special formula for that or a magic wand. He just demands hard work and wants every player to reach their very best form and that may be in a certain way they haven’t reached yet.

“For example, when people say Pep has made Lahm, Neuer, Boateng, Douglas Costa or Kimmich better players there is an important aspect we must highlight: they were already good players. What Pep has done is create the ideal working conditions in the training sessions and matches so those players reach their maximum potential. The same thing will happen at Manchester City.”

The challenge at City is different to that at Barca or Bayern, as Perarnau acknowledges. “When Pep started managing Barça in 2008 he had a team that was depressed and defeated, but that had a clear ideology: the La Masia way of thinking with Xavi, Iniesta and Puyol. What Pep did was put all his strength into empowering that ideology. He empowered Messi and he managed to win it all.

“When he arrived at Bayern he was faced with a champion team after the Jupp Heynckes’ treble, an excellent team. What Pep did this time round was change the way they played but made the most of the players’ characteristics.

“At City it’s a different scenario to the two previous cases. It isn’t a defeated squad because they were Champions League semi-finalists, but then it isn’t a winning side either. City hasn’t got a defined ideology of the game. Pep will put in place a long term plan so as to develop the players’ virtues, give the team his idea of positional football adapted to England and turn City into a great competitor.”

Guardiola, too, will come with a mind open to the realities he will encounter in a league that puts a premium on pace and strength. “This is going to be his toughest challenge yet,” says Perarnau.

And will his change his thinking? “Of course he will. Pep isn’t a dogmatic manager, quite the opposite,” says Perarnau. “There’s a wrong assumption about Pep, entirely wrong. They see a manager enslaved to a dogma of the game, fixed and inflexible, a kind of aesthete, and that is a big mistake. Pep is a born competitor and his main objective is always to win and he will change everything necessary to reach that objective in a fair manner.

“That’s what he did in Germany. He was like a chameleon. He adapted to German football and succeeded in making his Bayern play in different ways and be efficient. Having said that, Pep thinks his ideology on positional football is a very useful and efficient tool to compete in the long term in all tournaments. In other words, he will make City play like that and won’t give up on his football philosophy. But he will also adapt to the English reality in all necessary ways.”

One constant is that Guardiola will put everything into the task before him. Thin, almost cadaverous, his anxiety on the touchline can be glimpsed by the television viewer. Perarnau has scrutinised him for years and admits Guardiola pays a price for his devotion.

“Pep exhausts himself because he works too much. I don’t know if that’s a virtue or a defect. In any case, it’s part of his personality and he won’t change because to be able to perform at his best he needs all that previous intense work,” he says.

“If you take away Pep’s passion for work he would be a worse manager, so he won’t change in that regard. He demands the players have the same dedication and sacrifice he has.”

The writer believes coaching is more a “vocation than an obsession” with Guardiola. “Pep is happy being a manager. If you watched him during his first training session with City you will see his eyes sparkle. You may think that this passionate man hasn’t been coaching for 10 years and that’s why he is still so passionate. But that’s not the case. He only left Bayern 45 days ago. Managing is his passion.”

This passion will be tested at Manchester City. This is a club sustained by extraordinary wealth through its Abu Dhabi owners, and playing in the most high-profile league in the world in terms of television coverage. Guardiola, no stranger to examination or celebrity, has thus walked on to a stage in front of an audience of billions. He, too, inherits a side that has under-performed consistently, particularly in the Champions League, though City did match Bayern last year by reaching the semi-finals of the world’s premier club competition.

“Pep is totally aware that Manchester City is his toughest challenge yet as a football manager. This is the most complicated situation he has to deal with, the one that will be most demanding on his energy, passion and skill,” says Perarnau.

“This is also the challenge that needs more time to develop in its entire dimension. I would be very surprised if we saw Pep’s real City in the first year. I think he will need three seasons to get where he wants to be with Manchester City.”

It promises to be an exhilarating journey for the wandering coach. The destination will be extreme glory or a dismal failure marked by merely finishing second in whatever competition. There are no half measures for City. There are no half measures for Pep Guardiola.