Manchester United, Milan and Paris Saint-Germain are among the major European outfits who are due to farewell high-profile players when free agency comes into force on June 30.
Domestic leagues across the world appear increasingly likely to run beyond that deadline, meaning sides up and down the divisions could be forced to renegotiate deals beyond the typical expiry date.
It remains to be seen how governing bodies will approach the unfamiliar territory but Edinson Cavani, Mario Gotze and Zlatan Ibrahimovic will be watching closely like dozens more across Europe's top five leagues.
These are the stars and solid supporting cast members whose contract situations are worth monitoring in England, France, Germany, Italy and Spain.
LaLiga
Athletic Bilbao: Aritz Aduriz (retiring), Benat, Mikel San Jose
Atletico Madrid: Antonio Adan
Espanyol: Ander Iturraspe
Granada: Roberto Soldado
Real Valladolid: Hatem Ben Arfa
Sevilla: Ever Banega (joining Al Shabab at end of contract), Nolito
Valencia: Ezequiel Garay
Villarreal: Santi Cazorla
Premier League
Bournemouth: Ryan Fraser
Burnley: Joe Hart
Chelsea: Olivier Giroud, Pedro, Willian
Liverpool: Adam Lallana, Nathaniel Clyne
Manchester City: David Silva (confirmed he will leave at end of contract)
Manchester United: Nemanja Matic, Timothy Fosu-Mensah, Odion Ighalo (loan ends)
Newcastle United: Matty Longstaff
Tottenham: Jan Vertonghen, Japhet Tanganga
Serie A
Atalanta: Jose Luis Palomino
Hellas Verona: Fabio Borini
Inter: Ashley Young
Juventus: Gianluigi Buffon
Milan: Lucas Biglia, Giacomo Bonaventura, Zlatan Ibrahimovic
Napoli: Jose Callejon, Dries Mertens
Bundesliga
Bayer Leverkusen: Charles Aranguiz
Borussia Dortmund: Mario Gotze, Lukasz Piszczek
Hertha Berlin: Salomon Kalou
Schalke: Benjamin Stambouli
Wolfsburg: Robin Knoche
Ligue 1
Lille: Loic Remy
Monaco: Jemerson
Nice: Walter Benitez, Arnaud Lusamba
Paris Saint-Germain: Edinson Cavani, Thomas Meunier, Tanguy Kouassi, Layvin Kurzawa, Thiago Silva
Haaland has scored 78 goals in his two years with Dortmund – only Robert Lewandowski (107) has more in Europe's top five leagues – and would be a major coup for Madrid.
But while the Spanish giants remain confident of bringing in the in-demand striker from Dortmund, it could have a negative knock-on effect.
TOP STORY - HAALAND IN, BENZEMA OUT?
Karim Benzema is a much-loved figure at the Santiago Bernabeu and is enjoying another impressive campaign, but El Nacional claims that Madrid risk losing the Frenchman.
The report suggests that Benzema does not like the fact that president Florentino Perez is so fixated on bringing in a new player to lead Los Blancos' attack from next season.
While the 34-year is not currently seeking an exit, that could change should Madrid reach a pre-contract agreement with Haaland in the coming weeks, as has been suggested.
Benzema would not feel the need to move on should Kylian Mbappe join, though, as he considers that case to be different given the PSG striker is set to become a free agent.
ROUND-UP
– Barcelona accept that it is increasingly likely Ousmane Dembele will leave Camp Nou as a free agent at the end of the season. According to Sport, Manchester United and Juventus have held talks with the player's camp, while Chelsea and Bayern Munich have an outside shot of signing the forward.
– Arsenal have made their first move to sign Dusan Vlahovic from Fiorentina, with Corriere Della Sera reporting that the Gunners have tabled an offer of £50million (€60m) plus Lucas Torreira, who is currently on loan with the Serie A side.
– Chelsea are interested in signing Layvin Kurzawa on loan as they look to bolster their full-back ranks. However, Fabrizio Romano claims that the Blues have not yet officially opened talks with PSG.
– Calciomercato reports that Man Utd forward Anthony Martial has emerged as a January target for Juventus. The France international has struggled for games this season and has openly admitted he wants to find a new club this month.
– Everton are on the lookout for a new manager after parting company with Rafael Benitez on Sunday and hope to make a swift appointment. According to ESPN, former boss Roberto Martinez – now in charge of the Belgium national team – is the leading candidate to take over.
– Newcastle United have already brought in Kieran Trippier and Chris Wood this window, but The Telegraph reports that they have been knocked back in their bid to bring in Donny van de Beek on loan. The Man Utd midfielder is said to have been put off by the Magpies' position in the Premier League.
