When Paris Saint-Germain made their world-record €222million move for Neymar, Barcelona were caught off guard as the Ligue 1 giants paid the forward's release clause and left the Catalans powerless.
Barca could only sit and watch as the Brazilian made his exit, stepping from the shadow of Lionel Messi in the hope of one day usurping his former team-mate and Cristiano Ronaldo in the battle for the Ballon d'Or.
But Barca appear to have learned from their mistakes with respect to release clauses and the opportunity they present clubs willing to spend big.
Thursday's confirmation of Gerard Pique's contract renewal also brought news that the Spain defender's clause has been boosted to a whopping €500m, while Ousmane Dembele and Philippe Coutinho - signed since Neymar's departure - also have extraordinarily large sums attached to their deals.
Every player in Spanish football has to have such a clause in their contract and, while they do not always come into play in a transfer, they can give clubs an automatic position of strength - or weakness.
Here, we examine the biggest release clauses in football and, although transfer fees continue to swell, it will probably be a while before we see any of these figures matched...
€1billion - Cristiano Ronaldo and Karim Benzema
It will not come as a huge surprise to learn that no player has a bigger release clause in their contract than the reported €1bn in Ronaldo's. After all, the five-time Ballon d'Or winner is reportedly obsessed with the idea of being paid more than his rival Messi, so also wanting a larger clause than him is hardly a shock.
His Madrid team-mate Karim Benzema is also understood to have a €1bn release clause, though the club will not have to worry about another team triggering that, given he has just 13 league goals since the start of last season.
In fact, neither of the players have been particularly effective this season, with the pair scoring six times between them in La Liga. For that sort of figure, you could buy the entirety of almost any football club on Earth.
€700million - Lionel Messi, Isco and Marco Asensio
When Messi entered the final year of his Barca contract in July last year, the club remained publicly very calm about the prospect of him leaving on a Bosman deal at the end of the 2017-18 season.
Perhaps it was never really in doubt, as they did eventually tie him down in November, but there have since been murmurings of Real Madrid keeping tabs on the situation beforehand.
But Barca managed to insert a €700m release clause into Messi's deal. It might not be on the same level as Ronaldo's, but it should be enough to deter bidders, while the same can be said of Madrid's two Spanish jewels in Isco and Marco Asensio, who have identical figures in their contracts.
€500million - Gareth Bale, Gerard Pique, Luka Modric, Toni Kroos and Dani Ceballos
Pique's new deal places him among this elite group of players. The centre-back signed on for another four-and-a-half years and it will cost potential suitors half a billion Euros to prise him away from Camp Nou.
But four Real Madrid players already have clauses for the same amount in their contracts, highlighting that Los Blancos have been rather more prepared than Barca for the situation that arose with Neymar's departure.
Gareth Bale - once the world's most expensive player - is among them, with Luka Modric, Toni Kroos and Dani Ceballos - a July acquisition from Real Betis - also boasting hefty €500m buyout clauses.
€400million - Ousmane Dembele and Philippe Coutinho
Dembele and Coutinho are living proof of Barca's determination not to get caught off guard like they did with Neymar ever again.
Signed for €105m and €160m, respectively, the pair are Barca's two most expensive purchases ever, and they are not about to let them escape without a mind-boggling fee coming in.
Granted, €400m is the smallest in this list, but Barca can feel safe in the knowledge that - at least for the time being - it is a figure any club would struggle to meet.
