For a list of confirmed transfers, check out the transfers page.
Liverpool face competition to land Paris St-Germain's 24-year-old midfielder Javier Pastore, as Roma and Lyon are also chasing the Argentine.
Real Madrid will try to sign Manchester City striker Sergio Aguero, 25, for £48m next summer.
Hull City are looking at Serbia international striker Filip Djordjevic, 26, as a potential solution to their goalscoring problems. Djordjevic plays in France for Nantes.
LA Galaxy striker Robbie Keane will not be allowed to go out on loan to a Premier League club during January and February. The 33-year-old played seven games for Aston Villa during Major League Soccer's close season in 2012.
Manchester City right-back Micah Richards, 25, will consider his future at the club because of his lack of first-team chances.
West Brom's Congolese midfielder Youssouf Mulumbu, 26, has hinted he could be on the move in January after revealing that several clubs have enquired about him.
Manchester United are ready to offer Dundee United £3m plus three pre-season friendlies for Ryan Gauld, 17, who is also interesting Spanish giants Real Madrid.
West Ham manager Sam Allardyce says the club made bids for Romelu Lukaku, on loan at Everton; Newcastle loan signing Loic Remy; Chelsea's Demba Ba; and Stoke's Marko Arnautovic during the last transfer window.
Tottenham boss Andre Villas-Boas, who took at the White Hart Lane club in July 2012, will be sacked within the month if results do not improve.
Swansea manager Michael Laudrup and Sunderland boss Gus Poyet will be part of a Spurs shortlist if the London outfit decide to replace Villas-Boas.
Former England manager Fabio Capello is also being considered as a potential replacement for Villas-Boas.
Fulham manager Martin Jol says he is "worried" about his side's poor form and is unsure about his future at Craven Cottage following Saturday's 3-0 defeat by West Ham.
Sheffield Wednesday manager Dave Jones is on the brink of losing his job after just one win in 16 league games.
Celtic captain Scott Brown, 28, says he wants to commit his future to the club. The Scotland midfielder has 18 months left on his current deal.
Swansea City's Spanish forward Alvaro Vazquez, 22, wants to extend his loan spell in Wales - despite failing to find the net since joining from Getafe in September.
Derby's Championship trip to Wigan is set to be a family affair, with twins Will and Michael Keane preparing to make their debuts - on opposite sides, with the players both on loan from Manchester United.