For a list of confirmed transfers check out our transfers page.
Paris St-Germain want Chelsea's David Luiz, 26, to partner Thiago Silva in defence. Chelsea may be keen to sell Luiz as new manager Jose Mourinho is not convinced about the Brazilian's abilities.
A player leaving Stamford Bridge could be John Mikel Obi, with the Blues midfielder in talks with Galatasaray about a move to the Turkish club which could be worth £16m.
Chelsea have entered the race for striker Robert Lewandowski of Borussia Dortmund, who do not want to sell the 24-year-old to Bundesliga rivals Bayern Munich.
Manchester United's new manager David Moyes will have a £60m transfer fund to reinforce the Old Trafford club's squad.
Arsenal and Tottenham target David Villa, 31, will remain at Barcelona, according to the Spanish club's president Sandro Rosell.
Spurs are in talks with Corinthians for £17m-rated Brazilian midfielder Paulinho, 24, after going cool on Guarin of Inter Milan, due to the Italian club's demand of £21m for the Colombian.
Arsenal boss Arsene Wenger would be prepared to break the club's £15m transfer record to sign Real Madrid striker Gonzalo Higuain, who is valued at £25m by the Bernabeu club.
Borussia Monchengladbach say they are not interested in signing Arsenal striker Nicklas Bendtner, 25. The Dane, who spent last season on loan at Juventus, has a year left on his current contract.
Inter Milan are considering a move for Manchester City left-back Aleksandar Kolarov, 27, who has been kept out of the City side by Gael Clichy.
Manchester City are looking at Lazio defender Radu, 26, as they look to offload both Kolarov and Joleon Lescott.
Liverpool are stepping up their efforts to secure Armenian midfielder Henrikh Mkhitaryan from Shakhtar Donetsk, who could ask for a fee of £20m for the 24-year-old.
Reds striker Andy Carroll is expected to complete a £15.5m move from Liverpool to West Ham this week.
Sunderland boss Paolo Di Canio is looking to bring in 10 players during the transfer window, while keeper Simon Mignolet, 24, and midfielder Stephane Sessegnon, 29, are set to leave the Stadium of Light.
Newcastle's 31-year-old centre-back Fabricio Coloccini, who was keen to leave the club in January to return to his native Argentina, says he will stay with the Tyneside club.
Manuel Pellegrini has targeted Champions League glory at Manchester City after admitting there will be no excuses for failure after succeeding the sacked Roberto Mancini at Etihad Stadium.
Barcelona fitness coach Fernando Signorini, who has worked with the Argentina national team, has warned that Lionel Messi could suffer from burn-out ahead of the 2014 World Cup in Brazil.
Rupert Murdoch's global broadcasting companies are exploring an ambitious plan to create a summer football competition featuring Europe's top clubs, including English Premier League sides, with matches to be played around the world.
Liverpool manager Brendan Rodgers was left stumped by an interview with a nine-year-old after the fan's questions about misbehaving players and pocket money.