For a list of confirmed transfers, check out the transfers page.
Real Madrid plan to make a £25m move for Manchester United striker Wayne Rooney, 28, in the summer when he enters the final year of his contract.
England international Rooney will not sign a new deal with United even if they bolster their squad with the acquisition of Chelsea playmaker Juan Mata, 25.
Manchester United are ready to break their transfer record with a £37m bid for Spanish midfielder Mata, but Chelsea are thought to want £40m for the player they bought from Valencia for £23.5m in 2011.
Atletico Madrid hope to hijack United's attempts to sign Mata by offering David Moyes first option on striker Diego Costa, 25, and Brazilian full-back Filipe Luis, 28, if they drop their interest in the Chelsea midfielder.
Arsenal hope to sign Benfica striker Rodrigo, 22, from Benfica but face competition from Valencia and Zenit St Petersburg.
Lille have had a bid rejected for Sochaux full-back Sebastien Corchia, who is also wanted by Arsenal. The 23-year-old is under contract until 2015 but has hinted at a move to a bigger club in Europe.
Republic of Ireland midfielder Wes Hoolahan, 31, says he wants to leave Norwich City, despite the club rejecting his transfer request.
The Canaries are thought to be weighing up a move for Lazio's France international defender Michael Ciani, 29.
Centre-back Joleon Lescott, 31, will be allowed to leave Manchester City before the end of the transfer window if manager Manuel Pellegrini can secure a replacement.
Bayern Munich defender Dante, 30, says Manchester United have shown an interest in signing him in the January transfer window.
However, the Brazilian's agent, denies that a deal has been agreed with United and that Dante's first option is to agree a new contract with Bayern.
Stoke City are closing in on the £5m signing of Sunderland midfielder Lee Cattermole, 25.
The Potters are reportedly considering recalling Cameron Jerome, 31, from his loan at Crystal Palace if they fail to attract another striker before the end of the transfer window.
Newcastle are hopeful of clinching a loan deal for Borussia Monchengladbach's Netherlands international forward Luuk de Jong, 23.
That move may be more likely after Dutch giants Ajax and PSV Eindhoven pulled out of a move for De Jong.
Atletico Madrid manager boss Diego Simeone says he is willing to pay whatever it costs to keep Chelsea goalkeeper Thibaut Courtois, 21, when his loan spell runs out at the end of the season.
Liverpool are considering a loan bid for AC Milan midfielder Nigel de Jong, 29, as a replacement for the injured Lucas Leiva, 27.
Sporting Lisbon and Juventus are interested in signing Manchester United winger Nani.
Brighton have targeted Northern Ireland international Chris Baird, 31, as a potential replacement for Adam El-Abd, who joined Bristol City last week.
Swansea manager Michael Laudrup is likely to leave the club at the end of the season regardless of whether they are relegated.
Fulham manager Rene Meulensteen is confident midfielder Steve Sidwell, 31, will end speculation about his future by signing a new deal at Craven Cottage.
West Brom fear striker Nicolas Anelka, 34, may quit football if he receives a lengthy Football Association ban for his controversial 'quenelle' gesture.
Arsenal are set to offer Czech midfielder Tomas Rosicky, 33, a new deal to ward off interest from Bayern Munich.
QPR boss Harry Redknapp has urged Tottenham to decide the future of 21-year-old midfielder Tom Carroll, who is on loan at Loftus Road.
Former Manchester United midfielder Sammy McIlroy believes David Moyes can build his team around Juan Mata, if they can persuade the Chelsea man to move to Old Trafford.
Cardiff City midfielder Gary Medel, 26, knew just what to do after missing the team bus home from the 4-2 Premier League defeat at Manchester City - he jumped on the train with the fans.
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