Transfer fees in world football have gone through the ceiling since 2017.

Neymar's record-breaking move to Paris-Saint Germain has grossly inflated the transfer market and seeing players move for nine-figures is no longer the stuff of fantasy.

And one of biggest consequences of the transfer market's evolution is the change of release clauses in tandem, so they can match the heftier fees being thrown around by top clubs.

Besides, European juggernauts don't want a mass exodus of their best players just because their contract details are behind the times. 

And seeing as there can be no telling how much transfer fees will continue to rise, the likes of Barcelona and Real Madrid have conjured up some eye-watering release clauses.

World's biggest release clauses

In fact, the ten largest prices needed to unlock footballers from their current deals, barring negotiations stipulating otherwise, all emanate from Spanish football's two biggest clubs.

But who are the players in question? Well, the Daily Mail has answered that very question this week and we feel pretty confident that you'll be surprised when you find out the answers...

10. Gerard Pique - £423 million

Despite being 33 years old, Pique remains one of the best centre-backs in the world and he's the only defender on the list after Barca slapped him with this eye-watering fee as part of his 2018 deal.

9. Gareth Bale - £423 million

Considering Zinedine Zidane is desperate to ditch Bale, don't be surprised if the astronomical clause in the Welshman's contract is dispelled by a legal loophole much like the 18 he putts at each week.

8. Marco Asensio - £592.5 million

No chance anybody is paying half a billion for Asensio when he's spending his days on the treatment table, but his incredible talent could see his valuation creep into nine figures when he returns.

7. Isco - £592.5 million

It's rare that a week goes by without Isco being linked to the Premier League, but Los Blancos must temper their expectations if the plateauing Spanish midfielder is going to leave any time soon.

6. Vinicius Jnr - £592.5 million

Perhaps in a crazy, crazy world, this release clause won't seem so crazy in a few year's time. At the moment, though, you get the feeling Real have overrated their Brazilian youngster at this stage.

5. Lionel Messi - £592.5 million

It only makes sense that one of the greatest players of all time is given a top-tier biggest release clauses, even though he's now aged 33 and could be permitted to talk to other clubs in the summer.

4. Brahim Diaz - £634.9 million

What the flaming heck? Diaz has always been a top talent at Manchester City, although he's struggled since moving to Spain, but this seems as though somehow fell asleep on the keyboard.

3. Luka Modric - £634.9 million

While it might seem logical to give a recent Ballon d'Or winner an extraordinary release clause, there's no denying that Modric is on the decline and will likely leave Real on a free eventually.

2. Antoine Griezmann - £677.2 million

We're pretty sure this is just a consequence of Griezmann's transfer occurring so recently, but perhaps Barca view him as the heir to Messi's throne once their current number one fades away. 

1. Karim Benzema - £846.7 million

A surprise, no doubt! It would almost take £1 billion for anybody to pry away Real's biggest source of goals since Cristiano Ronaldo's departure, despite the fact Benzema is now 32 years old.

GIVEMESPORT's Kobe Tong says

Wowsers, Real Madrid truly have a fetish for massive release clauses.

Forking out more than £500 million for Diaz is like paying for a bag of crisps with a £50 note and saying: 'keep the change.'

Plus, you've got to imagine that Benzema and Modric's astronomical fees will surely be bypassed in any negotiations over the next few years considering they're creeping deeper into their thirties.

Otherwise, Real will have to concede some of their star players on free transfers when their contracts expire or angle for half-billion bids in a world where pigs are flying. 

And that's the point really, your release clause is only as useful as the length of the contract it's in.

Barcelona could go one minute laughing in the face of bidders for Messi with a whopping £592.5 million deterrent to handing him over loose change the next. Even the GOAT has his price.