Guardiola feels like he wants to leave Barcelona - the club which is in his heart. To do that, you gotta suspect that something isn't quite right there? So Barcelona move on - but where to? Who do they bring in, that could instantly match the respect with Pep had amongst that squad? It's a very, very short list. And whoever does come in, they're on a hiding to nothing as Guardiola has set such a high bar; with that comes unrealistic levels of expectation, and therein pressure. People react in funny ways when under pressure, and what's to say that the current squad might not like how a new manager dealt with it?
If Messi starts to feel unsettled, then why wouldn't he fancy a move? If Guardiola pops up at another high profile club with strong financial resources, then why wouldn't Messi feel drawn to go and work with a manager who believed in him, and brought him so much personal success? I certainly wouldn't rule any sort of move out - history has shown that loyalty is few and far between; both - it has to be said - from the players, and from the fans.
As I said - nothing in football lasts forever.
Guardiola left as a player because something was wrong. He is leaving as a manager because he is working 24/7, he's in an extremely stressful job and he doesn't want to get totally burned out. He was working hard for Barca B before he took over the first team, so he just wants a break. I'm sure he'd have preferred to go out on a high, but he's been on 1 year rolling contracts this entire time and he has always said that he would only continue if he felt he could continue at 100%, also that he could do the job asked of him. He has a 3 year old daughter that he hasn't spent much time with too. But you never know, he could return in a couple of years as a director of football or some other role like that. He could also come back in case of an emergency. That club is his national side more than Spain was, he said he only played for Spain because there wasn't an international team for Catalonia. (
http://en.wikipedia.org/wiki/Catalonia_national_football_team - That one doesn't have Fifa or Uefa approval, but fudge me that's a good team.
) So Barca is the team closest to his heart and due to things being the way they are in Spain, he'd never be the manager of Spain. He might be the manager of that Catalonia national team though, they only do friendlies, so there's less stress and he can take more time off.
Bizarrely, he has this really weird affection for English football. He wanted to come here as a player, but ended up going somewhere else after a friend asked him to help out, so he might try to manage here, but I don't know what with.
Emirates Marketing Project - Yaya Toure went on record of saying he'd never want to work with him again. (Quite a lot of ex Barca players have said this, Bojan was one of the more vocal ones.) This is potentially a good technical side, he could bring in players suited to his system and there's a lot he could do here.
Man United - If SAF retires then he could possibly work with this side, but Man United doesn't really have the ability to shift the many players that wouldn't work with Guardiola's style and bring in new players.
Chelsea - Fair play won't let him buy a new Chelsea team. Besides, I don't think Guardiola would particularly like it there, there are such epic changes needed too. Chelsea aren't his favourite team anyway, but I'm not sure he'd like that teen movie cliche of turning an ugly girl into the prom queen. He would help with the youth setup though.
Arsenal - The basic start of a system, but lacking the players required. Guardiola once said he had an entire B team of Jack Wiltsheres, how would he deal with having a team in which Jack Wiltshere is one of his better players? He can improve their system, motivate the players better, improve a ton of things about this side, but he'd die of frustration.
Liverpool - It's probably pointless to even outline the basic reasons why he isn't suited there... It's hard to think of things that would suit him there.
Saudi Sportswashing Machine - No, just no. Even picturing this is crazy. It might be a fun project for him, but Saudi Sportswashing Machine can't bankroll it.
Finally us, we can play his style, our youth setup isn't anything like what he's used to, he could bring players in, but I think we'd drive him nuts.
He won't return for a long time, so it's hard to predict which other clubs might be on that list in England. If Swansea somehow are competing for CL football in 4 years, maybe they'll suit him more than most, but it's hard to see how they'd find the resources he'd need, on the pitch they might suit him, but off the pitch it's not even going to be close unless they suddenly find a few million more fans and get a richer owner with a lot of cash to invest. (That's also assuming they're playing the same way.)
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Well, Messi is loyal, insanely loyal, but he owes Guardiola some loyalty too and Guardiola is probably the best manager Messi has ever had as far as 1 to 1 management goes.
But Messi has always said he wants to stay at Barca for as long as possible and when he's too old and brick to play for them anymore, he wants to go back to the club he was at in Argentina when he was about 12.
Messi is of the opinion that Barca gave him his chance, so he wants to repay them. I honestly feel that the worse things at Barca were, the more he'd want to stay to help... That said, all his friends that he grew up with are at Barca.
But even putting all that aside, if Emirates Marketing Project offered ?ú250 million for Messi, would Barca take it? If they offered Messi ?ú500k a week wages, would Messi take that? I think without Guardiola being at City, the offer wouldn't really matter to Messi, he'd rather stay at the club he's at with the team that was designed around him.
If the team fragments first or Guardiola first takes his friends and then offers Messi a chance to join, maybe that'd turn his head, but I still think he's loyal to Barca through and through.
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The thing is Guardiola is pure Barca, and as I say they are a unique set up. How would he get on trying to build a midfield with Parker and Sandro for example?! I have doubts as to how successfull he will be elsewhere.
Well, Barca B had the Barca set up, so he had players with extremely good technical ability to work with. All Barca teams play in the Barca style so the youth players don't have to learn new systems and styles when they move up a rank, so it wasn't a huge change...
He's worked with far less talented players, but as far as technical ability goes, the only people that lacked the technical ability of Barca players were signings rather than youth products.
As for a midfield of Parker and Sandro, considering none of the Barca players were CBs until later in their development (Puyol was a winger, etc), you could see him trying to play Sandro as a CB.
But he'd be fine with that, he has Keita and Busquets, he used to have Yaya Toure, he's had plenty of DMs to work with, they're usually taller than Parker, but he likes having a DM or two around... He might make Hudds a DM though, I could totally see that.
There are several really really bad things about Guardiola as a manager which are clear negative points, but he has so many plus points that anyone looking to hire a manager will feel outweigh the negatives. I think Guardiola will be a success wherever he goes, but I don't think he can turn Everton into the next Barca. He is a great manager, he is exceptional at motivating his team, he's very good tactically, he gets so much out of his players and his players want to play for him.
His Barca B team record is absolutely insane. His management style and the way he can make teams so much more than they were is amazing. I don't think there is anyone but Mourinho that can guarantee trophies wherever he goes, but Guardiola is a very very very very good manager, when you consider how many hundreds of managers there are that have managed in the top leagues, it's hard not to rank Guardiola in the top 10-20, some might rank him 3rd-5th and that's really hard to gauge, but he is in my top 10 comfortably.