Now, as you digest Barca's vast expenditure on Philippe Coutinho, try to recall how well the projects to replace those key players have gone -- or, in some instances, what they cost.

Nobody's talking about identical replacements for these club legends, just the most intelligent, appropriate and successful "what's next" footballers possible. Take the best, by far, of the Puyol candidates, Javier Mascherano. He has become a brilliant leader, a super-smart defensive lynchpin but when he joined back in 2010, he was told by Pep Guardiola "you do realize that you're not going to get many games, don't you?"

As good as the operation was to convert the midfield "Jefecito" ("little boss") into the central defensive "Big Chief," it was a combination of fluke and ingenuity. Not a purchased solution.

Xavi is Xavi. Literally a footballing genius. Not only have Barca not replaced him in any like-for-like sense, but they've barely even tried.

Villa? From his demise to an horrific broken leg in December 2011 until the immense striker was properly replaced by Luis Suarez, it took three years. Like "Masche," the Uruguay international was a controversial signing. He had to demand that he was allowed to move to the Camp Nou and he was also to be found at Liverpool.

As for Alves, his loss to the Blaugrana is more recent but it hasn't yet been handled. Like the other examples of the "golden age," he's exceptional, an all-time talent. But the fact remains that a club aspiring to be in the elite one percent of world football every single year and not an intermittent interloper, the "impossible" task must be confronted and successfully completed.

So, to Coutinho.

Of that "golden era," there are other remnants. Lionel Messi, naturally. And the club has just invested in their biggest-ever salary and incentive package to ensure that they can retain their footballing Da Vinci and not have to "replace" him.

Sergio Busquets is in a similar category. Occasionally other squad members occupy his position, either when he rests or is suspended, but the club also dug fantastically deep into their financial planning strategy in order to tie his unique talents to Barça until 2021.

You see the pattern. And you can see who's left.

Barcelona are attempting to make a big new deal for Gerard Pique, but it's clear that he is a guy upon whom they try to enforce certain contractual conditions that irk him. Not only that, but the arrival of Samuel Umtiti seems to have made some on the board think that the France defender can become not only the first true Puyol successor, but someone who decreases their absolute need to allow Pique to have the leverage when it comes to negotiations.

Then there is the little maestro, Andres Iniesta. The hub of the team... and the hub of this matter. Yes, they've shown they acknowledge his vital footballing, spiritual and symbolic importance by giving him what the Camp Nou executives liked to call a "lifetime" contract. But no financial investment can adequately fight Father Time. Of the last 131 La Liga matches, Iniesta has started just 70. And given that he's 33 years old, that ratio will decline.

Therefore, you can see why it is that Coutinho has been deemed worthy of an initial €120 million outlay and the likelihood of paying a third of that sum again in variable objectives.

Coutinho isn't Iniesta, of course, but can you think of a greater facsimile anywhere on Planet Football?

Where there are deficiencies, Iniesta's football brain and his cantera background, there are also positives: Coutinho's superior goal-scoring skills, his established ability to link with Paulinho and Luis Suarez. Plus, of course, his age. There's more. Coutinho almost exclusively plays on the left for Liverpool but for the Brazil national team, he now regularly performs in attacking right midfield.

Right now, Ernesto Valverde can call on a number of options there, principally Ivan Rakitic and Sergi Roberto. But there will be days (and soon) when Barcelona choose to line up with their right-to-left midfield reading: Coutinho, Busquets, Iniesta. And that's another clear indication of Coutinho's value to a club that is breaking their transfer record for the second time in half a year.

Barcelona's golden era -- and by that I mean from a viewpoint of the football they played to please neutrals, not just the trophies they won for their fans -- was largely based on the advantages a possession-based 4-3-3 can offer. For quite some time now they've not been able to play three in midfield plus three up front successfully. Their inability to keep the ball anywhere near as well as in the epoch-making days of prime-time Xavi, prime-time Iniesta and prime-time Busquets has compounded the fact that their squad has consistently been constructed with an eye to technique, not athleticism, height or power.

Valverde's remedy has been as evident as it has been smart: four starters in midfield (often Rakitic, Busquets, Iniesta and Paulinho) but supplanted with full-backs who flood midfield and, you know it, Messi doing the best version of Xavi we're ever likely to see. The downside has often been Suarez looking hugely isolated up front and now it's the team, not the ball, that does the work. But the system has made Barcelona ever so hard to beat.

With Coutinho fit, acclimatized and fully on form, there will be a big incentive for Valverde to ask Messi to play further forward and, more importantly, for the coach to gradually experiment with three up front.

Why is that so important? Because the man who was Barcelona's most expensive signing just a few hours ago but is currently second, Ousmane Dembele, has just got fit again and wants to play. Not only to justify the €100m outlay on a relatively inexperienced 20-year-old, but to let the former Dortmund forward learn, grow and start to impact on the team's trajectory.

With Coutinho, Barcelona can often play 4-3-3. Without him, the re-introduction of the young France forward was a far, far greater risk.

There's also greater flexibility, too. Should Valverde wish, he can play a four-man diamond midfield with Coutinho in behind Suarez and Messi: a formation to scare even elite teams like Manchester City, Bayern, Manchester United and Paris Saint-Germain, I'd say.

There are other things to say that begin to make it much more digestible and comprehensible why Barcelona, a club that doesn't have the financial resources to complete its next two big objectives, namely signing Antoine Griezmann and renovating the Camp Nou for upwards of €500m, would choose this record-breakingly expensive course of action.

For all that this will hurt Liverpool, their current competitiveness and the "fab four" brand that was developing so nicely under Jurgen Klopp, Coutinho has other fish to fry.

Like every prominent Brazil player, he's free to imagine that Tite's team can win the World Cup in Moscow next July. If Coutinho was this determined to move to the Camp Nou, having developed mystery injuries in the summer and then as soon as this transfer market opened up, his desire to move now and to establish himself over the next five months rather than to be involved in last-minute negotiations just ahead of joining up with the Canarinha is understandable.

On the other side of the coin, Barcelona can now reasonably claim that they've replaced the most high-profile Brazil/Nike product, Neymar, with the second-highest-profile candidate. For Nike's part, they've moved a 25-year-old "genius in the making" from a club that is equipped by New Balance to the football club/outfit in which they are most invested.

When the bank transfer is activated, the risk will feel magnified. Barcelona have gone out on a limb with this one, particularly for a footballer who is ineligible to help them try and win this season's Champions League and at a time when, in all reasonableness, they shouldn't lose their La Liga lead with or without Coutinho.

But he's the right guy. And if you're absolutely sure that you've got precisely the right guy, then the price will, in all likelihood, prove to be the right one too.

The timing isn't ideal, but where would football be, especially the modern Barca footballing brand, without creative risk?