The landmark 1995 Bosman ruling immortalised an otherwise obscure Belgium footballer and changed the sport he played forever.
In the 21 years that have followed, the likes of Robert Lewandowski, Andrea Pirlo, Sol Campbell and even Lionel Messi have all utilised this freedom. Will the names of Trent Alexander-Arnold, Virgil van Dijk and Mohamed Salah be added to this list next year?
The terrifying prospect moves closer to a reality for Liverpool as January 1 approaches and the trio are able to agree pre-contracts with foreign clubs. Last week, French outlet L'Equipe claimed that Salah, who is enjoying his most productive season at Anfield, would be open to a move to PSG.
Meanwhile, rumours of Alexander-Arnold's switch to Real Madrid have swirled for the better part of a year. Arne Slot will be desperate for the club to agree new terms with his side's most important players. But on the evidence of Salah's recent comments, in which he claimed to not have heard from anyone regarding a new deal, his title-chasers could look very different next term.
Liverpool's predicament is only unique because of the number of players in their starting roster with deals expiring at the end of the term but they are not the only club that will be sweating over the future of their players as the new year approaches.
Ahead of the start of the winter transfer window, Mail Sport takes a look at a formidable out-of-contract XI.
GK: Manuel Neuer
The legendary goalkeeper finally called time on his international career after Germany's exit from Euro 2024. After making 124 appearances, and drawing the ire of his countryman Marc-Andre ter Stegen, the 38-year-old decided to turn his attention to club football.
And despite his age, Neuer continues to be the man between the sticks for Bayern Munich, who have their sights on returning to their former glories, but for how much longer?
The shot-stopper reportedly has no intention of making this season his last in the game and according to Bild, he and the club will sit down for contract discussions in the spring. Clearly they're not fearful of losing him to a rival.
The German outlet also claim that Neuer hasn't even completely ruled out returning to the national team in time for the 2026 World Cup.
Alternatives: Andriy Lunin, Alex Meret
RWB: Trent Alexander-Arnold
If Liverpool fans were given 'Sophie's Choice' and forced to pick from their expiring-contract trinity, Alexander-Arnold would surely be the selection.
The 26-year-old has started the season in magnificent form as he enters his prime years.
Alexander-Arnold has been a topic of discussion for many seasons now, first lauded for his all-action full-back play and then derided for his poor defending. Finally, under Slot, he appears to have found the perfect balance.
Real Madrid seem to be the one and only alternative to Alexander-Arnold remaining in Merseyside and his close friendship with Madrid star Jude Bellingham continues to add anxiety that he too will soon call the Bernabeu home.
There is still confidence that he'll pen a new contract and emulate his hero Steven Gerrard in one day captaining his boyhood club. But Liverpool have been here before, in 1999. And on that occasion, Steve McManaman left for the Spanish capital.
Alternatives: Denzel Dumfries, Kyle Walker-Peters, Davide Calabria
CB: Virgil van Dijk, Jonathan Tah, Harry Maguire
A centre-back pairing of Van Dijk and Tah would instantly give your team one of the meanest defences in any division - adding Harry Maguire to it certainly raises questions but it's formidable nonetheless.
Van Dijk has reclaimed his position as the best defender on the planet after regaining his form following an ACL injury in 2020.
Having recently turned 33, the Liverpool skipper still has plenty left to give and while on international duty in September appeared to state his desire to extend his stay at Anfield. He told local media: 'At both teams, I am still Virgil van Dijk, the big leader, and I certainly want to remain that for the next two years.'
Tah, meanwhile, missed just one game as Xabi Alonso's all-conquering Bayer Leverkusen side captured their first Bundesliga title last term. The Spaniard has managed to retain most of his key contributors, avoiding the exodus many feared.
That instead may come next term, with the 28-year-old Tah first out the door and likely headed to the Allianz Arena and Bayern Munich.
Harry Maguire, who remains the most expensive defender in history, completes the central-defensive unit as he enters the final few months of his Manchester United contract.
There is still a possibly that he remains at Old Trafford on lower wages but it looks to be best for both parties to end their time together this summer. The 31-year-old came close to joining West Ham in 2023 but under new management, that prospect appears remote.
Despite lapses in concentration and ball-playing deficiencies, Maguire can still make a big impact for a team that plays to his strengths. Let's see if he can find the right one next term.
Alternatives: Victor Lindelof, Olivier Boscagli, Eric Dier
LWB: Alphonso Davies
Bayern Munich didn't take too kindly to Alphonso Davies' reluctance to sign a contract extension in 2023. The Canadian was a breakout star when the German giants won their sixth European Cup in 2021.
But three years on, his time in Bavaria could be nearing its end. According to his agent Nick Huoseh, Davies was close to a new deal before the Bayern hierarchy was replaced.
The 24-year-old has been a mainstay in the Bayern starting XI under Vincent Kompany this season, which indicates that he might have a future at the club after all.
Alternatives: Ferland Mendy, Leif Davies, Sergio Reguilon, Tyrick Mitchell
CM: Kevin De Bruyne, Joshua Kimmich
It wasn't supposed to go this way for Kimmich and Bayern. Admittedly, unfair comparisons were made with Philipp Lahm when he first joined the club from RB Leipzig in 2015.
A versatile defender with a superb passing range and poise on the field, Kimmich looked set to wear the red of Bayern for the rest of his career.
Kimmich is currently without an agent and though he's getting support and advice, interested clubs will have to directly contact him.
Manchester City, Arsenal and Liverpool are reportedly on the list of clubs Kimmich will consider joining alongside Barcelona and Real Madrid.
City are in need of midfield reinforcements, especially if their talisman Kevin De Bruyne opts to call time on his spell at the Etihad. After missing the first half of the last campaign with a hamstring injury, the 33-year-old has endured another frustrating campaign for the struggling Premier League champions.
Pep Guardiola was forced to deny that he has fallen out with the Belgian after he remained on the bench for the majority of their 2-0 defeat by Liverpool on Sunday. The signs are not the best.
A six-time Premier League champion and two-time Player of the Year, he has already secured his place among the best players to ever grace the division.
Alternatives: Thomas Partey, Angel Gomes, Frank Anguissa, Sean Longstaff
RW: Mohamed Salah
Speaking of Premier League legends, Salah may have fewer titles than De Bruyne but his impact on the English top-flight has been just as much profound. Salah could climb as high as sixth in the Premier League's all-time scoring charts by the end of the season.
Give him a couple more and you wouldn't bet against him becoming only the fourth player to reach a double century. The Egyptian might by 32 years old but his Cristiano Ronaldo-esque discipline means he's likely to keep performing at the top level for several seasons to come.
Salah has given plenty of indications of the fact that he'd like to remain at Anfield in recent months, including a report in The Athletic that he'd be willing to accept a one-year deal. We'll soon find out if this is his last dance with the Reds.
Alternatives: Leroy Sane, Paulo Dybala
LW: Neymar
It is strange learning that Neymar and Salah are the same age. In fact, the Brazilian is four months Salah's senior and will be 33 before his eye-watering contract, fit with unspeakable perks, comes to an end next summer.
If Ronaldo's move to Al-Nassr marked the beginning of the Saudi Pro League splurge, Al-Hilal's capture of Neymar marked the high-water mark. The former PSG forward moved in a deal worth £78million but his time in the Middle East has been a disaster.
The Brazilian suffered an ACL injury in only his fifth game for the club. He made his return in October this year, but suffered another injury setback in early November, which had led to reports that he may be released from his £130million-a-year deal at Al-Hilal in January.
It has been some fall-off for a player who was previously seen as the heir to Lionel Messi.
For Neymar, though, it represents a chance to finally get going with the Saudi side, for whom he has played only played seven games in over a year, and prove himself deserving of a new contract.
Alternative: Rayan Cherki
ST: Dominic Calvert-Lewin
The legend - if it can be described as such - of Calvert-Lewin was built during the 2019-20 season when he scored 13 goals and perhaps more shockingly, made 36 league appearances.
The following season, he improved on his tally and scored 16 times, though his league appearances reduced to 33. A healthy number, nothing to worry about.
Then came the 2021-22 campaign when two prolonged spells out restricted him to just 17 games in the top-flight. In fairness to the England international, his injury record improved markedly last term. The only problem was that goals were a little harder to come by.
So far this term, the 27-year-old has notched just two goals from the first 13 league games for an Everton side that look destined for another relegation scrap.
If he can rediscover his scoring touch of a couple of years ago, he is sure to have suitors in the summer.
Alternatives: Jonathan David, Callum Wilson