It's no secret that Barcelona star Lionel Messi is edging towards the end of his contract and seemingly on his way out of the Nou Camp for the first time in his senior career. Now 34, Messi may not be the all-conquering extraterrestrial he once was but there's no doubt interest in his services will be rife in the new year. Once the January window reopens, clubs from outside of Spain will be allowed to approach Messi and negotiate a contract ahead of the expiration of his current deal. Shrewd Football Manager enthusiasts will know the value of securing a Bosman free transfer before the end of the season, but the prominence of those types of signings in the virtual world does not seem to mirror what happens in reality.Despite this, the appeal of a free transfer in a hyper-inflated transfer market requires little explanation, so clubs will certainly be analysing their potential options and keeping a close eye on contract negotiations as 2020 edges towards its conclusion.But what other valuable players on the market will see their contracts expire in June 2021?Here at GiveMeSport, we consulted Transfermarkt to round up a list of the 24 highest valued soon-to-be free agents in world football. Check out the list of players below in ascending order from least to most valuable...24. Fabian Schar (Value: £11.7m)
Newcastle United centre-back Fabian Schar has only started three Premier League games so far this season and appears to be edging towards the exit door.The Switzerland international is a technically gifted operator and shone at the heart of the defensive unit during his maiden 2018/19 season with the club, scooping the North East Football Writers’ Association Player of the Year award in the process.According to The Athletic, Schar has frustrated his colleagues throughout his career and Bruce's selection policy points to a potentially terminal lack of trust. However, he has shown enough during his time with the Magpies to warrant another opportunity to impress in the Premier League, and it wouldn't be a surprise if a newly-promoted team took a chance on him next summer.23. Josh King (Value: £11.7m)
Josh King attracted plenty of interest from West Ham United in the summer following Bournemouth's relegation to the Championship. No move materialised in the end and the 17-goal Norway international will remain with the Cherries until January at the very least. Such is the extent of King's versatility and attacking prowess, he's unlikely to be short of top tier suitors in the event that Jason Tindall's side fail to return to the Premier League at the first time of asking.22. Elseid Hysaj (Value: £12.6m)
Napoli's Elseid Hysaj has previously attracted interest from Manchester United and Chelsea.The Albanian full-back is naturally right-footed but is capable of playing on both sides of the defensive unit. In a climate where high quality full-backs regularly command fees towards the £50m mark, particularly in the Premier League, signing Hysaj on a free would represent a shrewd piece of business. 21. Jesse Lingard (Value: £12.6m) 
You have to wonder if Jesse Lingard will get another chance with an elite outfit following his miserable decline at Manchester United. Inter Milan's tendency to hoover up United's debris suggests he may have a home at the San Siro under Antonio Conte, but he'll have to swap his part-time influencer career for lessons in tactical discipline to have any chance of securing that move. Having failed to make Ole Gunnar Solskjaer's Premier League squad in four of United's opening six games this season, the writing is on the wall for the 27-year-old attacking midfielder.20. Sergio Ramos (Value: £12.6m)
As Real Madrid celebrated their 34th Spanish title in July, Florentino Perez made it clear that Sergio Ramos will remain at the club, per AS."Ramos will end his career at Real Madrid. He is more than a captain."But the 34-year-old's contract situation remains unresolved and as things stand he will be a free agent next year. Everybody associated with Los Blancos will be praying for a new deal while some of Europe's super clubs look on from afar with intrigue. Will Ramos fancy one final challenge away from the Santiago Bernabeu? 19. Juan Bernat (Value: £14.4m)
Juan Bernat's CV speaks for itself and his availability is bound to stimulate some interest next year. The Spain international has won titles with both Bayern Munich and Paris Saint-Germain though he has struggled to firmly cement his place as first-choice during his time with both clubs. The flying left-back did, however, play a pivotal role in PSG's run to the Champions League final in the 2019/20 season, scoring two goals and providing two assists in ten starts.Manchester City's left-back struggles have been well documented in recent years, so perhaps Bernat is the solution they've been waiting for. 18. Otavio (Value: £16.2m)
With 16 goals and 38 assists in 152 appearances for Porto, Otavio has impressed with his creativity during his stint in Portugal. Wolves were reportedly interested in signing the attacking midfielder, who has worked with Nuno Espirito Santo in the past, during the summer window.A move failed to materialise but, if he opts not to sign a new deal with the Portuguese giants, it's unlikely Wolves will be the only side eyeing his signature. 17. Nikola Maksimovic (Value: £16.2m)
Nikola Maksimovic is currently embroiled in negotiations over a new deal with Napoli according to Italian media outlet Calciomercato.The 6ft 4 powerhouse's agent is reportedly demanding a salary that exceeds what Napoli are willing to offer, and the same report suggests the Serie A outfit may be willing to cash in on him in January rather than risk losing him for nothing next summer. Inter Milan, Everton and West Ham have all been credited with interest in the past.16. Eric Garcia (Value: £18m)
Eric Garcia's exit from Manchester City would sting for a club who so rarely bring players through the academy and into the senior squad.The 19-year-old is relatively inexperienced but plays with a maturity well beyond his years, showcasing an excellent ability to starve his opposite number in one v one situations and the type of technicality in possession that you'd expect from a Spain international.He's also regularly seen barking orders to his more experienced teammates.Man City will naturally want to keep hold of a future leader but Pep Guardiola has already confirmed that Garcia has no intention of agreeing to fresh terms.
15. Moussa Marega (Value: £18m)
Moussa Marega has been mooted as a target for several Premier League clubs in recent years but he's never made the move away from Porto.
The 29-year-old attacker, who is capable of playing as either a nine or a ten, may finally complete a long-suggested move to the Premier League upon the expiration of his current contract.
14. Henrikh Mkhitaryan (Value: £18m)
Henrikh Mkhitaryan has flaunted his creative qualities in the early stages of the current season, providing four assists in his first six Serie A outings.
The former Man United and Arsenal player agreed a one-year contract with Roma at the beginning of the season, and his impressive start will certainly bolster his chances of earning a fresh deal before the season reaches it conclusion.
His disappointing stint in English football is likely to deter interest from those shores, but his success in both Italy and Germany makes him an attractive free transfer option elsewhere on the continent.
13. Marten de Roon (Value: £20.7m)
Marten de Roon was one of the stars of Atalanta's exceptional 2019/20 campaign as the club finished third in Serie A and reached the quarter-finals of the Champions League.
In Gian Piero Gasperini's expressive and attacking-minded system the holding-midfielder has a pivotal role to play, so the club will be eager to tie him to a new deal.
Away from Atalanta there's bound to be a host of clubs monitoring De Roon's situation with interest.
12. Julian Draxler (Value: £21.6m)
There has long been a lingering sense that Julian Draxler's time is wasted at Paris Saint-Germain.
The Germany international, 27, is a creative and versatile talent who should be playing on a regular basis.
Injury problems and the strength in depth at PSG have restricted him to nothing more than fleeting spells of regular first-team football since he moved to the French capital in 2017.
With his contract due to expire next summer, now is the perfect time for Draxler to begin a new chapter.
11. Riqui Puig (Value: £22.5m)
Riqui Puig broke into Barcelona's senior setup at the beginning of 2020 and made five La Liga starts before the end of the 2019/20 season.
However, the 21-year-old has played just three minutes of league football since Ronald Koeman's arrival.
According to Fabrizio Romana (per Barcauniversal), the Catalan giants want to hand Puig a new two-year deal, but those reports are yet to translate into an official announcement.
Plenty of elite European outfits will be hoping to lure the talented prodigy away from the Nou Camp.
10. Arkadiusz Milik (Value: £24.3m)
The third Napoli player on this list is comfortably the most likely to depart.
Arkadiusz Milik was omitted from both Napoli's Serie A and Europa League squads this season, leaving him on the brink as his contract ticks towards expiry.
With a return of eight goals and four assists in 19 Champions League appearances, there is a bargain centre-forward deal waiting to be had right here.
9. Hakan Calhanoglu (Value: £27m)
Reports linking Hakan Calhanoglu with a move to Man United have swirled around the media in recent weeks and months, but The Athletic recently quashed those reports.
The Turkey international's agent is said to have contacted United's chief negotiator, Matt Judge, in a bid to force through a potential move, but the Red Devils have snubbed the approach due to their depth of options in attacking midfield.
With 27 goals and 40 assists in 138 games for AC Milan, though, he's unlikely to be short of suitors should be wish to leave the San Siro.
8. Florian Thauvin (Value: £28.8m)
Florian Thauvin has been a relentless goal contributing machine since leaving Newcastle United for Marseille.
A return of 81 goals and 56 assists in 247 games for Marseille speaks for itself, and it's no surprise that Marseille are reportedly desperate for him to tie him down to a new deal.
Following a glowing three-year stint in France, though, Thauvin may be inclined to explore the possibility of a move away from the club.
7. Angel Di Maria (Value: £28.8m)
Yet another talent who flopped spectacularly in England's top-flight before reinventing himself in France.
The marriage between Di Maria and Man United was short-lived, thoroughly underwhelming and financially disastrous, but that didn't stop PSG from offering him a lifeline.
Now into his sixth season in the French capital, Di Maria remains a fundamental player in Thomas Tuchel's squad.
It would be a surprise if the Argentina international was not offered a new deal before he is able to negotiate terms with rival clubs in January.
6. Georginio Wijnaldum (Value: £36m)
Liverpool's genie in the bottle could become one of the first lynchpins of the Jurgen Klopp era to bid farewell to Anfield.
Georginio Wijnaldum has been a beating heart in the Reds' midfield in recent years but the arrival of Thiago Alcantara and the rise of Curtis Jones suggest he may be reaching the end of an era.
According to 90min, Inter Milan and PSG have joined Barcelona in the race to secure what would undoubtedly be a shrewd free transfer.
Time is running out for Liverpool as the sharks begin to circle.
5. Sergio Aguero (Value: £37.8m)
One of the last remaining figures of Manchester City's old guard may well be the hardest to replace.
Sergio Aguero's absence through injury has clearly contributed to City's mediocre opening to the new season.
The four-time Premier League winners have missed his intelligent, darting movements, delicate interplay and, above all, his lethal finishing.
Despite Aguero's obvious credentials for a new contract, Pep Guardiola has, rather typically, challenged him to earn an extension.
Now 32 years old, perhaps the Argentine will instead realise his long-stated desire to return to his boyhood club Independiente.
4. Memphis Depay (Value: £40.5m)
Like Di Maria and Thauvin, Memphis Depay has also been a revelation since moving from the Premier League to Ligue 1.
The extent of the Lyon talisman's impact was laid bare in the summer amid reported transfer interest from Barcelona.
A move to the Nou Camp was "nearly done" by Depay's own admission, per The Independent, but the summer speculation appears to have had no bearing on his form.
The technically gifted attacking-midfielder has already scored five goals and provided three assists in nine games this season, banishing any doubts about his professionalism.
If he continues in this vein of form, Barcelona won't be the only club looking to sign him on a free transfer in 2021.
3. Gianluigi Donnarumma (Value: £54m)
With a colossal Transfermarkt value of £54m, AC Milan's Gianluigi Donnarumma is the 5th highest valued stopper in world football.
And it seems he's chasing a new deal that aligns with his status among the world's elite.
According to Corriere della Sera (via Football Italia), the 21-year-old's renowned agent, Mino Raiola, is trying to negotiate a deal worth €10m-per-season, and that could become a sticking point for a club who are actively trying to reduce their wage bill.
Given the sizable potential of the 20-cap Italy international, the Rossoneri could be set to lose a lucrative asset for nothing.
2. David Alaba (Value: £58.5m)
It has been widely reported that Bayern Munich recently withdrew their five-year contract offer to David Alaba after his representative rejected the long-term proposal.
The news has since turned into something of a fiasco following Alaba's own admission regarding Bayern's withdrawal.
Clearly, it seems there has been a fundamental breakdown in communication somewhere down the line.
Ahead of Bayern's game against RB Salzburg in the Champions League this week, Alaba expressed some regret over the situation in a pre-match press conference.
"I heard it like everyone else: on the news.
"I cannot say how it will continue from this point. I am glad to be playing for Bayern, and to be a part of the team. But what the future will look like after [what happened] yesterday evening, I just cannot say, as no one has talked to me officially."
A fine individual defender lies at the heart of this apparent power struggle, and his potential availability will no doubt have Europe's behemoths on tenterhooks in the coming weeks and months.
1. Lionel Messi (Value: £90m)
The one we've all been waiting for.
What does the future hold for the best football player of the modern era?
Unlike his perennial nemesis, Cristiano Ronaldo, Lionel Messi has never proved himself away from Barcelona.
Is that playing on his mind in the twilight phase of his career? His attempt to force a move away from the club in the summer window certainly suggested so.
With Messi's contract coming to an end in June 2021, the likes of mega-rich PSG and Manchester City will surely be drawing up provisional plans to approach him.
The footballing world is holding its breath.