Teams such as Borussia Dortmund, Manchester United, Valencia, PSV and AC Milan in particular will be keen to strengthen their team if the opportunity arises.
Any club looking to make some additions will have to act quickly, though, as they only have one month to get the players they are after.
The past two weeks have already seen a number of players switch clubs, but there's approximately two more weeks to go in most countries. Goal lines up the various deadlines across Europe.
|Germany 31 January 17:00GMT|
Bundesliga leaders Bayern Munich have yet to make any signings this winter after a successful first half of 2013-14, but the Bavarians did announce the capture of Robert Lewandowski from Borussia Dortmund on a free transfer at the end of the campaign, while Eintracht Frankfurt's Sebastian Rode will also make the move to the Allianz Arena come the summer.
Borussia Dortmund, meanwhile, have been linked with a number of replacements for the aforementioned Lewandowski, but are unlikely to add to their ranks this winter.
Schalke have signed Jan Kirchhoff on loan from Bayern, but are in risk of losing star player Julian Draxler amid interest from Arsenal.
Elsewhere, Wolfsburg brought in Junior Malanda from Zulte Waregem and have also captured Kevin De Bruyne from Chelsea.
|Spain 31 January 23:00GMT|
It's been quiet in La Liga so far as Barcelona and Real Madrid seem unlikely to make any signings this winter, despite the Catalans' search for a new centre-back and goalkeeper.
Second-placed Atletico Madrid, however, have brought in Argentine playmaker Jose Soso from Metalist Kharkiv.
Real Madrid youngster Alvaro Morata has been linked with Inter, Juventus and Arsenal, but seems destined to stay at the Santiago Bernabeu for now. It is a similar story for Fabio Coentrao, who has been attracting interest from Manchester United.
|Italy 31 January 23:00GMT|
There has already been plenty of action in Serie A, with struggling AC Milan in particular being quite active so far.
The Rossoneri have already secured the services of Keisuke Honda and Adil Rami this month, while offloading Alessandro Matri to Fiorentina.
Roma, meanwhile, have snapped up Belgium international Radja Nainggolan from Cagliari and consequently allowed Michael Bradley to move on to Toronto.
Inter finally completed the transfer of Argentine attacker Ruben Botta to add to their attacking options.
|France 31 January 23:00GMT|
The French top flight has plenty of spending power thanks to Paris Saint-Germain and Monaco and the latter have already made two interesting signings. They brough in Lacina Traore from Anzhi Makhachkala, though he is expected to go out on loan to the Premier League, while also signing Nigeria international Elderson Echiejile.
Paris Saint-Germain have been heavily linked with Paul Pogba, but are not expected to make a move for the Juventus midfielder until the summer.
Meanwhile, former PSG striker Guillaume Hoarau has returned to Ligue 1 with Bordeaux after a spell in China.
|UK 1 February 00:00GMT
Jose Mourinho's Chelsea are the big spenders of the winter window so far as they spent £20.7 million to secure the services of Nemanja Matic from Benfica.
Struggling Manchester United have been linked with a host of players, including Leighton Baines, Claudio Marchisio and Ilkay Gundogan, but have yet to make any big signings, though Anderson has joined Fiorentina.
Elsewhere, Shane Long and Nikica Jelavic have both found their way to Hull, while Jeremain Defoe is agreed to leave Tottenham for Toronto.
|Netherlands 31 January 23:00GMT|
There has already been plenty of action in Netherlands as Vitesse have signed Chelsea's Bertrand Traore on loan and Serbian youngster Uros Durdevic on a permanent basis. Gael Kakuta and Sam Hutchinson, however, have left the club.
PSV have strengthened their squad with Costa Rica star Bryan Ruiz, who has joined the Eindhoven side on loan from Fulham.
Furthermore, Sekou Cisse, Magnuss Wolff Eikrem and Stanislav Manolev have all left the Dutch top flight in January.
|Turkey 3 February 15:30GMT
Last year's winter transfer window saw stars such as Wesley Sneijder and Didier Drogba arrive in Turkey, but there has been less action this January, with Izet Hajrovic's transfer to Galatasaray arguably the biggest move so far.
Another remarkable signing is the arrival of Tunay Torun at Kasimpasa as the 23-year-old left Stuttgart for the Turkish top flight.