Chelsea will sign the French defender Kurt Zouma for £12.5m from St Etienne with a view to the player spending the rest of the season on loan in France before coming to London in the summer, as Jose Mourinho's rebuilding continues.
The deal, Chelsea's fourth signing of the window, puts further pressure on the situation of John Terry, the club captain, whose future beyond this season is yet to be resolved by the club.
Terry, 33, has been told that a decision has not yet been made on whether he will get a new contract and he is unlikely to get an answer until March.
Zouma, 19, will go straight into the first-team squad when he arrives at Chelsea. The club had originally planned on signing the Porto defender Eliaquim Mangala, with a strong interest in him last summer, but the Porto defender has been given a £38m valuation by his club, which Chelsea felt was unreasonable.
The deal for Zouma demonstrates how seriously Mourinho has taken the opportunity to continue his process of change at Chelsea this month. Nemanja Matic and Mohamed Salah have been brought to the club while Bertrand Traoré's future has finally been secured after he became eligible to sign a professional contract in the United Kingdom.
Zouma's arrival in the summer means that Chelsea can afford to be flexible when it comes to the futures of Terry and David Luiz. As ever, the director Marina Granovskaia will have a major part to play in liaising with owner Roman Abramovich over the futures of Terry, Frank Lampard and Ashley Cole – all of whom could potentially leave the club when their contracts expire at the end of the season.
Zouma, a France Under-21 international, has been on Chelsea's long-term list and fits their target profile of young talent acquired at a relatively low price. The defender has served a 10-game ban this season, laid down by a more flexible disciplinary system in France, for a tackle that left Sochaux's Thomas Guerbert with a broken leg and a dislocated ankle.
Fulham will sign the Tottenham Hotspur midfielder Lewis Holtby, beating Aston Villa to the player, who has had a medical at the west London club. Holtby could yet be followed out of Spurs by Etienne Capoue, in whom Napoli are interested, and the club would listen to offers for the striker Gylfi Sigurdsson and Nacer Chadli, who only arrived last summer, on the final day of the transfer window.
There remains interest from some of the hierarchy at Spurs in re-signing Dimitar Berbatov, whom Fulham are prepared to sell in this window before his contract expires in June. As it stands, it is unlikely that manager Tim Sherwood and technical director Franco Baldini would sanction a move for Berbatov. However, the option is there for Spurs chairman Daniel Levy and the former Manchester United striker is likely to be the subject of interest on the final day of the window.
Queens Park Rangers loaned Adel Taarabt - who has spent the first part of this season on laon at Fulham - to Milan in Serie A, one of the first major decisions by the Italian club's new coach Clarence Seedorf. Rene Meulensteen is also expected to break the club's transfer record on the Greek striker Kostas Mitroglou of Olympiakos for more than £12m. Mitroglou, 25, would be giving up the chance to play against Manchester United in the Champions League this season.
The strangest transfer deadline day stories - in pictures
The strangest transfer deadline day stories - in pictures
1/10 Peter Odemwingie to QPR?
One of the weirder stories of recent years. Odemwingie took it upon himself to drive to London from West Brom and spoke of his excitement about joining QPR. Unfortunately the Nigerian was to discover his club hadn't given him permission to speak to Harry Redknapp's side so Odemwingie suffered the indignity of being locked out of Loftus Road and sent back to the Hawthorns with his tail firmly between his legs.
2/10 Robinho's slip of the tongue
Newly rich Man City might have been pipped to the signing of Dimitar Berbatov in 2008, but they had made a big statement by stealing Robinho from under Chelsea's noses. So I expect they were delighted when Robinho announced: "Chelsea made a great proposal on the last day and I accepted". When asked if he meant Manchester City, Robinho replied: "Yeah. Manchester. Sorry!"
3/10 Ryan Babel's mystery flight
Ryan Babel was spotted getting in a helicopter bound for London on deadline day in 2010 but where was he headed? No move ever materialised and the mystery continues to this day. Just where was the Babelcopter going?
4/10 How much?
When Chelsea splashed £50m on Fernando Torres, in 2011, some felt they'd overpaid. Fortunately Kenny Dalglish and Liverpool were on hand to put things into perspective by immediately spending £35m of that money on Andy Carroll - a man with just a good half season of Premier League football behind him. Dalglish lost his job and Carroll is now at West Ham.
5/10 Julian Faubert to Real Madrid
Arguably one of the strangest transfers of all time, in 2009 Real Madrid took Julian Faubert on loan from West Ham. To the surprise of no one it wasn't a success, Faubert made just two appearances and once fell asleep while on the bench during a game.
6/10 Arshavin arrival
When that window slams shut (it always slams) trading ceases - unless you're Arsenal that is. The £15m arrival of Andrei Arshavin in 2009 had Gooners waiting for confirmation a full 24 hours after Big Ben had struck midnight. There was some excuse about adverse weather conditions, but that didn't stop Arsenal's Premier League rivals from raising an eyebrow or two.
7/10 David Beckham joins PSG
While any criticism of Sir David of course borders on sacrilege, and Beckham's decision to give all his wages from the club to a children's charity is to be applauded, the fact that he chose to make the move on deadline day when as a free agent he could move whenever he liked, did seem quite a lot like attention-seeking.
8/10 Benjani's airport nap
Sounding more like the badly thought through excuse of a schoolboy than a reason that almost scuppered a transfer, Benjani wrote his way into deadline day folklore in 2008. Flying from Portsmouth to Manchester to finalise a move to City, the striker rather unfortunately fell asleep in the airport, missing two planes and nearly ruining his chances of a move. In the end Man City fans must have wished he had.
9/10 Samba time
Nothing sums up the mad decisions made by desperate clubs during the January window than the signing of Chris Samba by QPR. The relegation threatened club forked out an incredible £12.5m to bring in the former Blackburn centre-back to save their season - and also agreed to pay him £100,000 a week. Turned out he wasn't much help, at one stage even having to apologise for being at fault for two goals in the west-London derby defeat to Fulham. QPR were relegated and Samba returned to Anzhi Makhachkala.
10/10 Alan Pardew's lucky day
Bizarrely and seemingly with a whiff of something shady, 2006 saw Carlos Tevez and Javier Mascherano arrive at West Ham looking more than a little confused. In the end the third party deal was ruled illegal and West Ham had to pay a £5.5m fine and £20m compensation to Sheffield United who were relegated when Tevez's goals kept West Ham in the league later that season.