If the off-season window of 2021 will be remembered for one thing beyond the number of big-name players who switched clubs, it will be how many made their moves on a free transfer.
Lionel Messi ended his association with Barcelona to join Paris Saint-Germain for nothing, with Gianluigi Donnarumma, Sergio Ramos and Georginio Wijnaldum all joining him at no extra cost.
Meanwhile, Cristiano Ronaldo sealed a return to Manchester United in a bargain buy from Juventus, far below the fee he would have once commanded during his Real Madrid days.
Stars moving after running down their contracts, however, has been a reminder of how bumper buy-out clauses help the world's biggest clubs keep their stars tied down.
A few major release deals were matched ahead of the 2021 season, of course, most notably Manchester City stumping up the £100m ($136m) needed to bring Jack Grealish to the club from Aston Villa.
There have only been a handful of such transfer fees met over the years, though - and many more players boast price tags far too steep for even the super-rich to pay.
But just who has the biggest release clause in business? Goal takes a look over what are reportedly the largest figures in the game.
| Rank | Player | Club | Reported release clause |
|---|---|---|---|
| 1 | Karim Benzema | Real Madrid | €1bn (£850m/$1.2bn) |
| 2 | David Alaba | Real Madrid | €850m (£726m/$988m) |
| 3 | Antoine Griezmann | Atletico Madrid* | €800m ($683m/$930m) |
| =4 | Federico Valverde | Real Madrid | €750m (£641m/$872m) |
| =4 | Luka Modric | Real Madrid | €750m (£641m/$872m) |
| =4 | Brahim Diaz | Milan** | €750m (£641m/$872m) |
| =7 | Marco Asensio | Real Madrid | €700m (£598m/$814m) |
| =7 | Vinicius Junior | Real Madrid | €700m (£598m/$814m) |
| =7 | Isco | Real Madrid | €700m (£598m/$814m) |
| =10 | Gareth Bale | Real Madrid | €500m (£427m/$581m) |
| =10 | Gerard Pique | Barcelona | €500m (£427m/$581m) |
| =10 | Sergio Roberto | Barcelona | €500m (£427m/$581m) |
*on loan from Barcelona
**on loan from Real Madrid
Given that clubs must give players a release clause in La Liga, it isn't too much of a surprise to see that sides from Spain dominate the list - but you might notice that there are no players from Ligue 1 on here.
That is due to it being illegal in France for teams to attach buyouts to their stars, meaning that talents like Kylian Mbappe, Neymar and Lionel Messi do not have such clauses.
| Player | Club | Reported release clause |
|---|---|---|
| Kevin De Bruyne | Manchester City | €250m (£213m/$290m) |
| Paulo Dybala | Juventus | €70m (£60m/$81m) |
| Bruno Fernandes | Manchester United | €100m (£85m/$116m) |
| Erling Haaland | Borussia Dortmund | €80m ($68m/$93m) |
| Harry Kane | Tottenham Hotspur | No release clause |
| Kylian Mbappe | Paris Saint-Germain | No release clause |
| Lionel Messi | Paris Saint-Germain | No release clause |
| Neymar | Paris Saint-Germain | No release clause |
The top ten in full
1. KARIM BENZEMA - €1bn (£850m/$1.16bn)
Never mind a world-record fee - any suitor would need to quite literally break the bank if they were to land Real Madrid's French superstar, who commands a significant release tag.
Given his blistering start to the season - arguably flourishing more than ever in a post-Cristiano Ronaldo era - it's no surprise that Carlo Ancelotti's side would want a king's ransom for his services.
2. DAVID ALABA - €850m (£726m/$988m)
The highest new entry, the Austria stalwart finally secured his move to La Liga ahead of the 2021-22 campaign, joining Los Blancos at Santiago Bernabeu after a decade with Bayern Munich.
If reports are believed too, he has now landed the second-highest release clause in the competition - and the continent - indicating his value to Madrid in the post-Zinedine Zidane era.
3. ANTOINE GRIEZMANN - €800m ($683m/$930m)
One of two players near the summit of this list currently on loan, the France striker sealed a shock return on a temporary basis to his old home of Atletico Madrid late in the transfer window.
There could yet be a different agreement for a full-time return should his spell go well, but Barcelona have otherwise had him in possession of their highest release clause.
=4. FEDERICO VALVERDE - €750m (£641m/$872m)
Brought from Penarol and blooded through the Castilla youth system, the Uruguay international has gradually established himself as a key player among the more experienced faces of Los Blancos.
It is possibly what his future holds that is why Madrid have handed him such a high release clause though, hoping to lock him in as he continues to mature going forward.
=4. LUKA MODRIC - €750m (£641m/$872m)
Even before he led Croatia to a World Cup final and broke the monopoly of Cristiano Ronaldo and Lionel Messi by winning the Ballon d'Or, the playmaker was already a hot commodity in the Spanish capital.
Despite being well into likely the twilight of his career, any potential rivals looking to poach Modric would still have to fork out an enormous sum for his majestic talents.
=4. BRAHIM DIAZ - €750m (£641m/$872m)
Like Griezmann, the midfielder - who earned his first senior cap for Spain during the summer against Lithuania - currently finds himself on loan in Serie A, having struggled to leave his mark as a youngster in La Liga.
But Madrid clearly did not want to easily lose him for the future, like Valverde, having slapped a massive price on his head should anyone else come hunting for his services on a full-time basis.
=7. MARCO ASENSIO - €700m (£598m/$814m)
A stalwart of Los Blancos since he arrived from Mallorca in 2014, the winger is arguably yet to reach the peak of his powers, and at only 25, he probably has more to give.
That will certainly explain why Madrid would want to make a sizable profit on him if he was to leave - and the size of his release tag pretty much ensures nobody will try.
=7. VINICIUS JUNIOR - €700m (£598m/$814m)
Another young gun that Los Blancos would be loathed to lose, the attacker is already on a long-term deal that will take him through to the middle of the decade at Santiago Bernabeu.
Having truly settled into life in La Liga now too, it is hard to think that he would be shown the door anytime soon either - which surely keeps him there for a while, given that hefty release tag.
=7. ISCO - €700m (£598m/$814m)
The Real Madrid midfielder is arguably slipping towards his twilight years rather than accelerating towards a rebirth - but he remains tied to a massive buyout clause at the Santiago Bernabeu.
=10. GARETH BALE - €500m (£427m/$581m)
A season-long loan back at his old stomping ground of Tottenham last year failed to spawn a full-time move back to the Premier League for the Wales international, even with the potential of a cut-price deal.
Spurs surely would not have bitten for the full cost of the forward's release clause though, which at half a billion euros now represents more the player he used to be rather than what he currently offers.
=10. GERARD PIQUE - €500m (£427m/$581m)
Whenever and wherever the 34-year-old hangs up his boots, he is sure to be feted as one of the cornerstones of Barcelona's success during the bygone Lionel Messi era, holding the fort at the back in defence.
As the most senior leader of the crop that remains following the Argentine's exit, he is fast approaching the end of his career - but the Blaugrana would still want an astronomical fee if he was to leave for new pastures with no questions asked.
=10. SERGIO ROBERTO - €500m (£427m/$581m)
It has been a steady climb to a regular spot among the top ranks at Camp Nou for the full-back but it is hard to deny that he has earned his shot over the last decade.
Barcelona certainly feel he has proved his weight in gold too, and have handed him a half-billion euro release tag, to ward off any clubs who fancy a cut-price move for the 29-year-old.
