The immediate thought is that it cannot happen. Mohamed Salah, the embodiment of this glorious period of Liverpool’s history, cannot be allowed to leave: the club have to give him whatever he wants. Just make sure he stays, keeps rattling along at 20-odd goals a season, many of which will be stunning, keeps delighting both fans and neutrals with his verve and imagination.

But the immediate thought may not be entirely helpful: no player is ever irreplaceable. Of course, there is a sentimental appeal to the idea that a player and a club have a special relationship, particularly when that player has been instrumental in a club’s rise, as Salah has been for Liverpool under Jürgen Klopp. But circumstances change. Liverpool’s history is a study in the importance of not becoming unduly attached to heroes, of moving players on at the right time.

By his own admission, Bill Shankly allowed his first great Liverpool team to grow old together, until the FA Cup defeat to Watford in 1970 shocked him into action. His successor, Bob Paisley, quieter but far more ruthless, never made the same mistake. When Kevin Keegan decided to escape the UK’s upper-rate income tax of 83% in 1977, Liverpool signed Kenny Dalglish.

The key to long-term management is to an extent knowing when to offload players – which is one of the reasons football can be such a brutal, apparently ungrateful, sport.

Similarly, Alex Ferguson never let players outstay their usefulness: he culled Mark Hughes, Andrei Kanchelskis and Paul Ince in 1995 and was just as swift to release Roy Keane a decade later. Even the very greatest can outstay their welcome. For all the wailing and hand-wringing when Lionel Messi left Barcelona, recent evidence is that a reset was long overdue: elite sides cannot operate at the pace of an ageing talisman. A glance at the slough from which Arsenal are beginning to emerge should be warning enough of the dangers of panicking and handing ageing stars inflated contracts.

That’s not to say Liverpool should be looking to sell Salah; rather that there should be a clinical assessment of whether the cost of keeping him is worth it. In terms of their squad, Liverpool have been run supremely well recently. That they have – just about – kept pace with Manchester City despite spending a net £220m less over the past five seasons is remarkable. They have been very good at keeping the budget in check; does it make any sense now to jeopardise that by meeting Salah’s demand to double his salary to £400,000 a week?

Mohamed Salah takes the second-minute penalty that put Liverpool on the way to winning the 2019 Champions League final against Tottenham
Mohamed Salah takes the second-minute penalty that put Liverpool on the way to winning the 2019 Champions League final against Tottenham. Photograph: Toby Melville/Reuters

Whether he deserves it is not really the point. Salah, of course, has a right to negotiate the best possible deal. Given he is one of the best players in the world, it follows that he should be one of the best-paid players in the world. He turns 30 in June: this will probably be his last major contract – why wouldn’t he try to ensure it leaves him as comfortable as possible for the rest of his life?

There is a romantic answer, which is that it might be hoped Salah had developed some kind of affection for Liverpool, for Klopp, for his teammates and for the fans. Would he not relish another Premier League title at Anfield – this time, perhaps, won with fans in the stadium? Would he not relish another Champions League success – this time, perhaps, with him on the pitch for whatever the equivalent of the 4-0 win over Barcelona happened to be? At what point do memories outweigh another few million pounds in the bank, or the domestic league winner’s medal that should come almost as of right with Juventus or Paris Saint-Germain, who appear the two favourites to sign him?

But there is also a more pragmatic answer that lies within the question of whether Salah made Liverpool great or Liverpool made Salah great. Clearly to an extent, it’s both. Salah is a magnificent footballer, a brilliant dribbler and a superb finisher. But as anybody who saw him wandering around listlessly for Egypt at the Africa Cup of Nations knows, it’s also true that he is unusually well-suited to Liverpool’s style of play; he is not guaranteed to be that good in any lineup. He looked a very good player at Fiorentina and Roma, but it is only since his move to Anfield in 2017 that he has become exceptional.

Roberto Firmino and then Diogo Jota have been adept at dropping deep to create room for him to swoop into, while Trent Alexander-Arnold’s surges outside have also helped generate space. But it’s also a matter of the whole style, the hard and high press, the dynamic midfield that wins the ball back early, that has helped.

Without a major overhaul, it can safely be assumed he wouldn’t have that at either PSG (deep-lying midfield to compensate for celebrity forwards) or Juventus (just not Massimiliano Allegri’s style). There are plenty of players whose big move hasn’t quite worked out, from Eden Hazard to Romelu Lukaku, Antoine Griezmann to Philippe Coutinho.

There is a tendency to assume that the quality of players is absolute when, in fact, it’s often contingent on circumstance, their value and form in part derived from the structure of which they are part.

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Salah may move on and thrive, but there are no guarantees. And while Liverpool would miss him, the form of Luis Díaz since his arrival in January suggests they could cope. The system looks strong enough now to endure the loss of any individual.