Virgil van Dijk
Southampton's elegant centre-back is a target for both Manchester clubs and Everton, who are managed by his former mentor Ronald Koeman. Southampton, though, have attempted to ward off potential suitors by putting a £60 million (€70 million) price tag on the defender.
Mamadou Sakho Liverpool
The French centre-back has fallen out of favour at Liverpool, having exhausted Jurgen Klopp's patience with his behaviour since his suspension for taking a banned substance. Lille, Galatasaray and both Milan clubs are interested in a loan deal.
Christian Pulisic Borussia Dortmund
Already a regular for the United States at the age of 18, Pulisic was subject to an £11 million bid from Liverpool last August. Klopp would love to sign the young winger, but Liverpool have been warned by Borussia Dortmund that they want to keep Pulisic until the summer.
His club manager Koeman claims Lukaku would not look out of place in the Barcelona side and is hoping he will sign a new contract. If he does not, a return to Chelsea looks the most likely of options for the 23-year-old. A prolific striker is top of Antonio Conte's priorities and Lukaku certainly fits the bill.
The 19-year-old midfielder has impressed for Porto this season, and has been linked with a move to Chelsea. Neves already has two Portugal caps, and featured
in Porto's recent 5-0 win against Leicester. He might be more likely to move in the summer.
Gylfi Sigurdsson Swansea
The darling of Swansea, Sigurdsson is said to be attracting interest from Serie A giants Roma and Inter Milan, while Leicester and Everton are both keen too. Given the Swans' current struggles, few would blame him for seeking a move.
Alexandre Lacazette Lyon
The French striker came close to leaving Lyon last summer amid interest from Arsenal and West Ham United. He has all but confirmed his exit for next summer, but it remains to be seen if a January offer can tempt him away.
Morgan Schneiderlin Manchester United
Effectively frozen out by Jose Mourinho at Old Trafford, Schneiderlin has no shortage of suitors if he wants to stay in the top flight. The most likely option is a switch to Everton, while West Brom are also keen on the French midfielder.
Bastian Schweinsteiger Manchester United
Has been brought back in to the first-team squad after being ostracised by Mourinho, but he has been limited to a single four-minute EFL Cup appearance. He remains keen to move away in January, possibly to MLS.
Memphis Depay Manchester United
Signed by Louis van Gaal in the summer of 2015, Depay has never fully settled at United and has barely featured in the Premier League this season.
Jose Mourinho is happy to let him leave, with Everton emerging as the most likely destination.
Branislav Ivanovic Chelsea
Closing in on a decade at Stamford Bridge, veteran defender Ivanovic has fallen down the pecking order under Conte. Should he opt to leave Chelsea, a number of clubs have been linked with a move, including Juventus, Besiktas and Crystal Palace.
Wilfried Zaha Crystal Palace
The Palace winger has been the club's standout player in a difficult season and Tottenham could renew the interest that first surfaced last summer, when a £12 million bid was rejected. Sam Allardyce does not want to sell, but a bid in excess of £25 million (€29 million) could force his hand.
Antonio RUdiger Roma
The tall Roma centre-back is an imposing figure on the pitch, with Manchester United and Chelsea just two of several big clubs tracking the 23-year-old. Again, a deal would appear more likely to happen in the summer.
Moussa Dembélé Celtic
Liverpool and Tottenham are keeping tabs on the pacy young French striker, who is enjoying a very impressive season under Brendan Rodgers, which continued on New Year's Eve with another goal in the Old Firm derby.
Michael Keane Burnley
The centre-back has been linked with a return to former club Manchester United, while Leicester and Everton are also reportedly interested. Burnley would be holding out for around £25 million (€29 million) though, and would be unlikely to accept an offer this month.
Jermain Defoe Sunderland
The 34-year-old striker has been in excellent form for Sunderland this season, and has been linked with a return to former club West Ham. David Moyes will, however, be very reluctant to sell his most prized asset as he plots the club's survival course.
Nathan Smith Port Vale
The highly-rated 20-year-old centre-back has reportedly been watched by Arsenal and Liverpool's scouts, having been touted as a future Premier League star by Bruno Ribeiro, the manager of his League One side. "For me, he is already a Championship player. In a few years, then Premier League," Ribeiro said. Watch this space.
Wilfried Bony Stoke
There is a clause in his Stoke deal that allows his loan from Manchester City to be cut short if a (presumably monstrous) bid is made from a Chinese club. Stranger things have happened, and Bony has not been in the Stoke side of late, suggesting that Mark Hughes could be preparing for life without him.
Alexsandr Mitrovic Newcastle
Napoli are reportedly planning an £18 million (€21 million) bid for the striker, who has found first-team opportunities at Newcastle limited thanks to the exceptional form of Dwight Gayle. West Ham and Crystal Palace are also reported to be interested.
Leonardo Ulloa Leicester
The Argentinian striker - one of the hardest workers in the top flight - is struggling for game time at the King Power Stadium, and Sunderland are weighing up a January bid. West Brom are also reportedly interested, and a move to China is a possibility. (© Daily Telegraph, London)