A stint at Real Betis has turned Isco's career around. CRISTINA QUICLER/AFP via Getty Images

In the complex world of transfers, there's something refreshingly simple about the idea of a release clause. Forget all the tense talks between clubs, the weeks of negotiations with presidents and sporting directors. You want a player? Pay their release clause, and they are yours!

At least, that's the idea. The reality, of course, is a bit more complicated. In Spain, almost all players have release clauses in their contracts, for legal reasons. In theory, it's the players themselves who make the payment as their representatives hand over the lump sum at LaLiga's Madrid headquarters; though in practice, it's the destination club which provides the cash.

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The release clause sum is supposed to reflect a player's transfer value, and setting the figure forms part of talks when agreeing to a new deal. A club would often want to set a clause prohibitively high, to make it effectively unpayable, although even that is unpredictable: Barcelona thought Neymar's €222 million clause was out of reach in 2017 ... until Paris Saint-Germain broke the world transfer record to pay it.

Nowadays, top players at Real Madrid and Barcelona have release clauses set at €1 billion, which would be considered extortionate even in today's inflated market. Other clauses are set at a more accessible figure, in agreement with the player, offering a fee considered acceptable for both parties as a way of planning for the future.

Clauses might vary, too, rising or falling depending on objectives secured like promotion, relegation or national team call-ups. In some circumstances, a club might even choose to pay more than a player's release clause, or accept less, in order to secure a more favorable payment structure.

As we head into the summer transfer window, here are some of LaLiga's most exciting players in 2024-25, their release clauses, and how likely they are to switch clubs in the coming months.

The United States international, 23, has had an outstanding season at Betis, becoming one of LaLiga's best all-around midfielders. Tottenham Hotspur hold a €25m option to sign the player -- agreed as part of the deal which took Giovani Lo Celso to Betis from Spurs last summer -- but Cardoso would have the last word on his future and, right now, it's Atlético Madrid who are the leading candidates. Sources have told ESPN that Atlético want to sign a No. 5 (a deep-lying central midfielder) and Cardoso fits the bill. They'd want to negotiate a reduced fee, but Betis might be open to that given their hurry to balance the books before the end of June.

Araújo, 26, flirted with leaving Barcelona in January -- with Juventus interested -- before signing a new contract until 2031. Indeed, he said when he joined up with Uruguay on Tuesday: "I'm one of the team's captains ... I'll stay." However, that doesn't mean the centre-back is certain to remain at Barça. He had an injury-hit season, missing the first half of the campaign and making just 12 LaLiga appearances, and there were some high-profile blunders, like in Barça's 5-4 Champions League win at Benfica. Coach Hansi Flick prefers Pau Cubarsí and Iñigo Martínez at centre-back, and Jules Koundé at right-back. And, reportedly, there's a mechanism in Araújo's new contract to allow a departure this summer for a fee of €65m, if the clause is paid before a certain (unconfirmed) date, after which it rises again.

ESPN reported in April that Arsenal were in advanced talks to sign midfielder Zubimendi and were confident of completing a deal. That's despite reports of interest from Real Madrid, whose new coach, Xabi Alonso, knows the player well from their time together at Real Sociedad B. Zubimendi, 26, is viewed as one of Spain's best midfielders and previously came close to joining Liverpool last summer, before opting to stay at his hometown club for one more year.

Williams, 22, has been on the radar of some of Europe's top clubs since starring for Spain at Euro 2024. Even after a somewhat underwhelming season with Athletic Club, he still represents a bargain. Barcelona were linked with the flying winger last summer, with club president Joan Laporta admitting he's "a player I like," although there were always doubts about their ability to raise funds for the deal amid their financial issues. This month, Marca claimed Real Madrid were keen, but it's a move which would make little sense given that they already have Kylian Mbappé and Vinícius Júnior. Athletic have qualified for the Champions League, which could persuade Williams to stay; otherwise, the Premier League would be the natural destination.

Atlético have been in talks with Villarreal over the signing of Baena since last week, sources have told ESPN. Baena has been a long-term target, with coach Diego Simeone a big fan. Once again, Atlético's objective in talks would be to negotiate a more favorable financial package, rather than paying the clause up front. Baena's stats over the last two seasons have been among LaLiga's best for a creative midfielder -- with 16 goal involvements both this season (seven goals, nine assists) and last season (two goals, 14 assists) -- and he would be a significant addition.

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LaLiga's best goalkeeper this season -- making the most saves (145) and preventing the most goals (8.40; a statistic reached by taking Expected Goals on Target Conceded, minus Goals Conceded) -- García is a star of the future. And he'll be a bargain for whichever club signs him. Espanyol avoided relegation last weekend, meaning his release clause stays at €25m, rather than dropping to an even cheaper €15m. It might even have risen to €30m if he'd made this week's Spain squad, but he inexplicably missed out. Arsenal tried to sign the 24-year-old last summer, and both Barcelona [a controversial move for an Espanyol player] and Real Madrid have been linked.

A bright spark in an otherwise disappointing season for relegated Las Palmas, creative midfielder Moleiro, 21, will surely now be on the move, with his contract due to expire in 2026. Scoring six goals from midfield was an impressive tally in a relegated side, while they tended to be goals of exceptional quality, showcasing Moleiro's impressive technique and habit of timing his runs into the box. Relegation means Moleiro's clause is now €30m, and the No. 10 would be a sensible replacement for Baena at Villarreal.

Ratiu, 26, is one of LaLiga's most underrated players. He doesn't get many headlines, but the Romania international might have been the best right-back in the league this season, helping Rayo to an eighth-placed finish and UEFA Conference League qualification. So naturally, there's speculation that he's likely to move this summer, despite having a contract until 2028. Ratiu was linked with Barcelona in January, but Villarreal also reportedly retain an option on their academy product. Ratiu's attacking profile would suit both clubs.

A candidate for LaLiga player of the season, Isco has seen his career revitalised at Betis. He's just been rewarded with a return to the Spain squad for the Nations League final four, six years after his last appearance, and the former Real Madrid midfielder has called Betis his "light in the darkness." The club took a chance on him after six months as a free agent -- following his contract at Sevilla being terminated in December 2022 -- and having helped them to finish sixth in LaLiga and the Conference League final this season, he's highly unlikely to want to move on.

For many, Ayoze was the signing of last summer in LaLiga. Villarreal brought in the experienced forward, 31, for an absurdly low fee of €4m from Real Betis, and he repaid them by scoring a remarkable, career-best 19 league goals -- making him the division's top scoring Spaniard -- as they qualified for the Champions League. On that basis, the forward might want to stick around.

Mingueza, 26, surprised everybody with his form for Celta this season, becoming one of Spain's most attack-minded full-backs, and is a key part of Claudio Giráldez's youthful side. That's reflected in his 10 goal involvements -- four goals and six assists -- in LaLiga this campaign. He's back in the Spain squad, too, having been out of the picture since 2021. Barcelona reportedly retain 50% of Mingueza's economic rights and, having been close to joining Aston Villa in January, you wouldn't rule out a move to the Premier League this summer.

Budimir is now an Osasuna legend. In January, he became the club's highest-scoring foreigner ever; in March, he became their highest scorer in Spain's top flight. This has been the best season of the 33-year-old's career, with 21 goals in 38 LaLiga games, ending the campaign behind only Mbappé and Robert Lewandowski. A player who's had a nomadic career at the likes of St Pauli, Crotone, Sampdoria and Mallorca now looks like an elite finisher, and that has sparked speculation about his future. He's even been linked to Real Madrid as a useful, "Plan B"-style forward, like Joselu in 2023-24. Budimir has a contract until 2027 and Osasuna would love to keep him.