It isn’t easy sometimes understanding why Pep Guardiola gives the impression that he is never fully satisfied with Sergio Agüero, and it is even more perplexing when we cannot be too far away from the Argentinian going into the record books as the most prolific scorer in Manchester City’s history.

As it stands, Agüero’s 170 goals in their colours leave him seven short of the highest total and, to put it into context, it took the record holder, Eric Brook, 11 years to accumulate that number, from 1928 to 1939. Agüero is just starting his seventh season in Manchester and is almost there already.

Even last season, when we were repeatedly told he was having a bad year, it was difficult to follow the logic. A bad year? Agüero managed 33 goals in all the different competitions, more than any other player in England with the exception of Harry Kane. It was one hell of a bad year.

There is no getting away from the fact, however, that at the same time Agüero is chasing down that 177-goal target his mind must be filled with a little self-doubt on the back of the club’s attempts to sign Alexis Sánchez – an upgrade, in the eyes of Guardiola – and the questions it leaves regarding his own position.

Not just when it comes to City, either. Agüero, the scorer of 33 goals in 82 caps for Argentina, did not play a single minute of his country’s goalless draw against Uruguay in the early hours of Friday. Even when his team were searching for a late winner, the Argentina coach, Jorge Sampaoli, decided he could get by without the City striker.

Yet the fact Agüero was even on the bench was actually progress, of sorts, bearing in mind Argentina’s games in June against Brazil and Singapore. Sampaoli, a few weeks into the job, left Agüero out of the entire squad and it might surprise you how uncontroversial that decision was. When the Argentinian sports daily Olé ran a poll in March asking which players should be dropped, 80,000 readers responded: Agüero had 86% of the vote.

Agüero, in other words, is going through a difficult and challenging period, for club and country. The two go hand in hand and this is why nobody should just pass off the latest stories about his discontent in Manchester as assumptions and hearsay on the back of City’s attempts to bring in another elite forward.

On the contrary, it has been apparent for some time that the relationship has been strained and that it predates the move for Sánchez. There is no warmth, little chemistry, not a lot of interaction. Agüero is no longer a mandatory pick and that, in turn, is threatening to have repercussions on his international career. The word in Argentina – where they are not exactly short of front players – is that nobody should just assume he will automatically be picked if or when the albiceleste get to the World Cup.

Amid all that nonsense with the steward at Bournemouth last weekend, the more relevant detail was that Agüero was left out of City’s starting lineup to accommodate Gabriel Jesus (just as he was last season). Agüero then headed off for international duty and when he returns to Manchester this coming week it will be in the knowledge that, if Arsenal had not dug in their heels, Sánchez could conceivably have supplanted him in the team to face Liverpool on Saturday. Of course Agüero is going to be wondering what all this means. Of course there are going to be moments of insecurity. Which footballer in that position would not feel that way?

If you find it all rather confusing, then join the club. Agüero was still the first player Zlatan Ibrahimovic mentioned – apart from himself, naturally – when he was asked recently to identify the best striker in the Premier League. Nobody has scored more goals for City in less time, or done more to elevate the club to a new level. He is still only 29, the age when many strikers reach their top level, and it is easy to understand if he feels bruised when the previous City manager, Manuel Pellegrini, treated him so differently.

The Chilean used to talk about Agüero being third on the list of modern football greats, outperformed by only Lionel Messi and Cristiano Ronaldo, and even if he was applying a little top-spin you knew why he was saying it: fluffing up the player’s ego, playing on the fact that all footballers, but strikers in particular, tend to do better when they are high on confidence.

Guardiola has taken a different approach entirely and it has been obvious ever since he replaced Pellegrini that the new manager did not care greatly if the players he disappointed were the ones with the greatest presence and personality.

Agüero scored 11 times in his first six games for the Catalan. Sure, there were compliments from Guardiola but, equally, there were follow-up remarks that stopped you in your tracks. What an important player, Guardiola would say, then a few sentences later there would be a line that felt puzzling and incongruous when it was unprecedented to hear a City manager, even one as forthright as Roberto Mancini, question Agüero’s contribution.

Even when Guardiola was invited to praise his player it was never articulated with the warmth that would be evident later on in his eulogies about Jesus or some of his other signings. To begin with, it wasn’t something you would necessarily pick up on. Then, after a while, it stood out like a sore thumb.

Is Agüero still the same player? Maybe not quite, but if there has been a slight deterioration it is only in the tiniest of fractions and the manager must take a degree of culpability, too. Guardiola’s demands that a 30-goals-a-season player change his style of play might form part of a tactical masterplan. It has also jarred the player’s confidence and created a situation where Agüero feels unfairly maligned, where he has started to feel sorry for himself and has been snatching at some of the chances he would ordinarily have been expected to put away. However it is dressed up, it is difficult to think of it as good man‑management.

Where all this leads is not so clear but a player of his standing would be within his rights to contemplate leaving in January, especially if there is an attempt to resurrect the failed deal for Sánchez. Until then, however, Agüero doesn’t really have a great deal of choice, this being a World Cup year, other than trying to prove his manager wrong.

He is more than capable of doing it. Yet it is also easier said than done sometimes when a player, especially a star player, feels unappreciated by his manager and, in fairness to Agüero, he is not alone when it comes to thinking his manager should cut him some slack. Jesus has bags of potential, undoubtedly. For now, however, there are not many people at City who would agree that the Brazilian is the superior player. Not yet, anyway.

The harsh reality for Agüero, however, is that if it were not for Jesus breaking a metatarsal at Bournemouth in February then it is more than likely the younger man would have finished that season as the team’s principal striker. Sánchez was seen by City as another central attacker. Jesus, already established as one of Guardiola’s favourites, occupies the same role and, at most, there is space for only two players in that position. Agüero, City’s record scorer in waiting, could be forgiven for wondering where he was supposed to fit in.

Hazarding a guess at Kylian’s prospects

Amid all the transfer business of the last week, what do we make of Chelsea’s surprise swoop – amid not a great deal of top-level competition, I would strongly suspect – for a 22-year-old midfielder from Ujpest of the Hungarian league?

The surname might be familiar: Kylian Hazard , previously of White Star Brussels and Zulte-Waregem in Belgium, who has been added to the Chelsea development squad even though you would ordinarily expect someone of that age to be in the manager’s first-team plans.

All for the greater good, perhaps, but it does leave a slightly awkward question about whether Chelsea would have given him a second look if he were not Eden Hazard’s younger brother and nobody should be surprised if the new signing makes precisely the same number of appearances as Thorgan Hazard, another sibling, managed in his three years on the Stamford Bridge payroll. That number being zero.

Anybody else suspect Chelsea are doing everything they can to make sure Eden does not entertain any thoughts of leaving? No doubt the club are also keeping tabs on 14-year-old Ethan, the youngest Hazard brother, currently to be found in the academy at AFC Tubize, just south of Brussels, and surely destined for a move to SW6 soon. But it does make me wonder what the younger players in the development squad, namely the ones who are there for orthodox reasons, think about it all.

Shame Roy wasn’t keen enough on FC

It is difficult not to admire the chutzpah of FC United of Manchester – the breakaway club formed after the Glazer family’s takeover of Manchester United – during those seismic days in 2005 when Roy Keane had trashed his team-mates on MUTV, fallen out spectacularly with the Old Trafford management and suddenly found himself out of a job.

The story is recounted in a new book, Red Rebels, by the club’s founder, John-Paul O’Neill, and tells how Keane’s first offer of alternative employment came in the form of an old-fashioned knock at the door and an invitation to be part of the new movement.

It was worth a go and Keane, you might be surprised, did not react too badly to two FC representatives wandering up his drive to ask if he wanted to join the fledgling club in the second division of the North West Counties Football League. Keane took a number and promised to think about it – “Would I have to do everything the manager tells me?” – before deciding in the end that the Scottish Premier League with Celtic might be a slightly better standard (insert your own joke here).

What a pity. Keane would have fitted in neatly with the idea of punk football and climbing up the ladder of English football (FC are only two stops off the Football League now). It would also have been a delight to see the reaction of Sir Alex Ferguson – a man who always seemed startlingly paranoid about FC’s success – on hearing the news. Just a guess, but I doubt he would have taken it well.