A new year. Another transfer window. A chance for stars to make future plans.
Players whose contracts are set to expire in June 2021 can speak to clubs from outside their own leagues from January to ensure that they are not left in the lurch come the summer.
Some clubs could look to cash in now, in fear of losing big names for free, while the ticking clock can kick sides into gear to try to reach an agreement and put pen to paper on fresh terms.
Here, Sportsmail takes a look at the high-profile stars who have just six months remaining on their current deals and where they might end up.
There's nowhere else to start. It is widely known that the six-time Ballon d'Or winner's contract at the Nou Camp is up in the summer. Lionel Messi tried to force through a move to Manchester City this year after handing in a transfer request but a switch failed to materialise amid the threat of legal action from the club.
Barcelona are still hopeful that they can tie down their superstar, who has been at the LaLiga giants since 2001, to new terms although presidential candidate Emili Rousaud recently revealed that Messi must take a pay cut or he will have to leave on the expiration of his deal.
Messi worked with City manager Pep Guardiola for four years in Spain and a reunion in the Premier League could be on the cards. French giants Paris Saint-Germain are also keen on bringing in the Argentine.
Possible destination: Manchester City
Could the potential arrival of compatriot Messi push City's all-time top goalscorer further towards the exit door? On the other hand what a mouth-watering prospect Aguero and Messi in attack in England's top flight is. The pair have been lining up alongside each other for Argentina since 2006.
However, Guardiola said earlier this season that Aguero must earn a new deal at the Etihad although negotiations over one are expected to be held. Aguero's fitness issues could become a determining factor in his future.
His 2020-21 season has been hindered by injury setbacks and the 32-year-old has started less than five matches since June. There is no doubting his ability at the highest level but City need a world-class No 9 who can play week in, week out. Aguero has a desire to return to boyhood club Independiente before he hangs up his boots.
Possible destination: Independiente
The Real Madrid captain has toyed with the idea of leaving the Bernabeu before. Manchester United and China were previous potential landing spots but Paris Saint-Germain appear to be in the mix this time around.
Real boss Zinedine Zidane has remained coy on Ramos' future and one of Madrid's greatest ever players is keen to sign a new two-year deal while Los Blancos' policy is to only renew contracts of players who are over 30 by a season. The centre half turns 35 in March.
Like many clubs Real are feeling the financial effects of the coronavirus pandemic and may ultimately have to get Ramos' wages off the books and the Spaniard does reportedly hold an unnamed offer from the Premier League, plus PSG are interested.
Possible destination: PSG
One player that could replace Ramos should he depart is Bayern Munich's David Alaba. The versatile Austrian looks set to leave Germany in 2021 after not reaching an agreement with Bayern.
The Bundesliga giants have appeared to have accepted defeat in trying to tie him down to a new deal and at 28-years-old there is expected to be a scramble for his signature.
Real look like the favourites to win the battle but PSG and Chelsea have also been mooted as possible options. Alaba, who has played at centre back in recent campaigns due to the emergence of Alphonso Davies but can play at left back and in midfield, has won two Champions Leagues as well as nine Bundesliga titles. What a steal he will be.
Possible destination: Real Madrid
The Liverpool midfielder was linked with a move to Barcelona in the 2020 summer transfer window as he entered the final year of his Anfield deal.
The 30-year-old has become a key figure for Jurgen Klopp and played a huge part in the club's success in recent years. In the 2018-19 season he was instrumental in Liverpool's sensational 4-0 comeback win over Barcelona in the Champions League semi-final at Anfield with two second-half goals. The manager wants him to stay.
Barcelona manager Ronald Koeman, who knows Wijnaldum well from his stint as Holland boss, is keen on bringing the Dutchman to the Nou Camp and the Catalan giants can make another move for him now.
Possible destination: Barcelona
Another star that Real could lose is Croatian midfield maestro Luka Modric. Although like Ramos the 35-year-old is in line to be offered a one-year extension.
Modric, who claimed the Ballon d'Or in 2018, still seems to be firmly in Zidane's plans after playing a pivotal role this season.
The midfielder believes he still has two years left in him at the top and has previously stated that he would like to finish his career at the Bernabeu.
Possible destination: No other clubs in the frame, likely to stay put
The Lyon forward was heavily linked with a switch away to Barcelona but he remained in France. Again like Wijnaldum, Memphis Depay is a player Koeman is familiar with from his Holland days and wants him to bolster his frontline.
The 26-year-old, who flopped during his time at Manchester United between 2015 and 2017, has flourished since making the move to Lyon and in turn become a crucial player.
Depay has recently dismissed speculation that he could leave the club in January for Barcelona but conceded 'many clubs' are showing an interest in him.
Possible destination: Barcelona
The 19-year-old defender was close to heading out of the door of Manchester City last summer but Barcelona reportedly failed to meet the club's valuation.
Eric Garcia has made it clear that he does not wish to extend his stay at the Etihad beyond 2021 and therefore it makes sense for City to cash in on the promising centre back during the winter transfer window.
The teenager, who has rarely featured this season, is reportedly eyeing a move to Barcelona, however the cash-strapped giants will be keen to get him for nothing come July.
Possible destination: Barcelona
The 27-year-old Germany international was sensationally linked with a move to Leeds last summer and also had offers from various sides in the Bundesliga.
He had no intention of cutting his time in Paris short but a new contract at the Parc des Princes is increasingly unlikely. He has suffered with injury this season and appeared to had fallen down the pecking order under Thomas Tuchel - before the manager was sacked on Christmas Eve.
Arsenal and Everton have also shown an interest in the midfielder in the past but the strongest suitors are based in his homeland.
Possible destination: Bayer Leverkusen or Hertha Berlin
The 21-year-old AC Milan goalkeeper is highly-regarded and the Serie A giants will be keen to tie him down to a new long-term deal as soon as possible. An extension at the San Siro is a probable outcome.
However, PSG have expressed an interest in the past and their current No 1 Keylor Navas is not getting any younger at 34. Donnarumma could cement his place as the Ligue 1 giant's first choice for several years to come.
Chelsea were linked with a move for the shot-stopper earlier this year due to the error-prone performances of £72m man Kepa Arrizabalaga. But they solved that problem position with the signing of Edouard Mendy from Rennes in the most recent transfer window.
Possible destination: PSG
Again Chelsea were interested in the Napoli right back but the Italian outfit did not choose to let him depart and could now lose him for free in July.
They reportedly could have received £43million for the right back last year from the Blues but did not take them up on the bid. Chelsea have their own talent in that position now in Reece James so are unlikely to try a second time.
Spanish side Valencia have been linked with Hysaj but their limited funds after missing out on European football and the impact of the coronavirus pandemic could restrict them in terms of meeting his wage demands even though they could get him for free. Premier League club Newcastle could be a potential destination although the defender is keeping his options open.
Possible destination: Valencia or Newcastle
P.S. There are plenty of other notable summer free agents...
Mesut Ozil - It's no secret that the former Real Madrid star is winding down his contract at Arsenal. The playmaker has been frozen out by manager Mikel Arteta, even though the Gunners are crying out for some creativity in behind the frontline. The 32-year-old wants to see out his contract in north London while Turkish side Fenerbahce, Inter Miami and LA Galaxy in MLS reportedly monitor his situation.
Angel di Maria - The PSG forward is expected to have no shortage of suitors over the coming months despite being 32. Angel di Maria continues to be an influential player for the French giants and has proven he can still do it a the highest level. Yes, he failed to deliver during his time at Manchester United but he seems to have put those struggles behind him. What a bargain he'll be.
Florian Thauvin - The 27-year-old remains a key player for Marseille, being both a creator and source of goals. It would be easy to forget that the Frenchman spent a short spell at Newcastle a few years ago. He's been linked him with a move to AC Milan should he not remain in France.
Hakan Calhanoglu - The AC Milan star is reportedly close to putting pen-to-paper on new terms in Italy. He had been linked to Manchester United in the Italian press but Sportsmail understands their interest was never serious. The 26-year-old attacking midfielder has developed into a key figure at the San Siro and they are keen to keep hold of him. Manager Stefano Pioli is confident he will sign a new deal.
Arkadiusz Milik - The Napoli striker is out of favour and the Italian side look set to cash in on him in January. Tottenham were interested in bringing the frontman to north London last summer but instead agreed a loan deal for Carlos Vinicius as back up for Harry Kane. Atletico Madrid and Juventus reportedly lead the way to sign Milik but may have to stump up £13.5m.
Henrikh Mkhitaryan - The former Manchester United and Arsenal man has put his struggles in England behind him by becoming an instrumental player for Roma. He has been in sensational form this season, racking up a host of assists as well as goals from midfield. Roma won't want to lose him and certainly not for nothing in July.
Riqui Puig - The emerging talent of Riqui Puig could already be on his way out of the Nou Camp. The 21-year-old has had limited game time this campaign and could be even further down the pecking order after manager Ronald Koeman accused him of leaking information, according to reports.
Jerome Boateng - It appears that Jerome Boateng's time at Bayern Munich is coming to an end. Although the defender would like to remain at the German giants there is no indication from the club that that is on the table. Tottenham, Chelsea and Arsenal have all been linked with a move for the World Cup winner, who endured a disappointing spell in the Premier League at Manchester City before heading to Bayern.
Edinson Cavani - The Uruguay forward made the surprise move to Manchester United last summer after becoming a free agent. Cavani provides cover for Anthony Martial, Marcus Rashford and Mason Greenwood at Old Trafford and United do have the option to extend his deal by one more year.
Diego Costa - The Atletico Madrid striker has been plagued by injuries this season and the club brought Luis Suarez to the club last summer, who has delivered as Diego Simeone's side have impressed. There are no indications where Costa may end up but what a parting gift winning LaLiga would be.
Jesse Lingard - The England international has fallen down the pecking order under Manchester United manager Ole Gunnar Solskjaer and although his contract is set to expire in June, the Red Devils are set to trigger the one-year extension clause to avoid losing him for nothing. It looks as though the midfielder needs a fresh start to recapture his best form. He has been linked to Sheffield United and Real Sociedad for a short-term loan stint from January.
Andros Townsend - The Crystal Palace winger has been an important player for the Eagles over the last four years. However, the Premier League club are in danger of losing him for free this summer. Palace did invest in exciting prospect Eberechi Eze last summer but Townsend, 29, would still be able to provide plenty of threat down the flanks for Roy Hodgson's side.
Christian Benteke - Another Palace player who could be heading out of the door is Belgian striker Christian Benteke. Although not the most prolific he continues to test Premier League defences. If the Eagles don't tie him down to a new contract they may well be coming up against him in the not too distant future. The forward can certainly still do a job in England's top flight.
Juan Mata - The third star United could lose but again they are in control as they can opt to extend the Spaniard's stay until 2022. The 32-year-old has been a wonderful player to watch in the Premier League over the years but has developed a bit-part role at the Red Devils.
David Luiz - The 33-year-old has been rotated by manager Mikel Arteta this season but David Luiz appears to be one of the leaders within the Gunners dressing room. Arsenal have had an abysmal first half of the campaign and with Luiz's future up in the air, his focus could drift elsewhere. Arsenal only splashed out £7m on the defender from Chelsea but could do with hanging onto him, and more importantly could do with not letting him go for nothing.