With Juan Mata's arrival at Manchester United and more big-money deals still possible, the title race could be vastly different come Friday's deadline.
One of the most well-worn cliches used by Premier League managers is that of a lack of value in the January transfer window and the difficulty in signing the very best players midway through the season.
Yet the next week could decide the destination of the title this season. Only two points separate the top three teams in the table - and it means the next few days could define the tightest title race in years.
Rarely has the winter window had any impact on the outcome of the Premier League. Manchester United supporters may point to Henrik Larsson’s loan move in 2007, but even then the Swede scored just one goal in seven league appearances.
You probably have to go back to November 1992 for the last time a midseason signing truly made a difference, when Eric Cantona moved from Leeds to Manchester United and helped the club to a first title since 1967.
So far, of the title protagonists, only Chelsea have been active in the transfer market. The Blues have re-signed Nemanja Matic from Benfica for 25 million euros to add steel to their midfield, while winger Mohamed Salah has completed his transfer to west London from Basel.
Jose Mourinho’s side looks well set, two points behind leader Arsenal and with money to spend should the opportunity arise to sign a top-class striker - how the Blues would love Atletico Madrid to part with Diego Costa this month - which is the only glaring weakness in the squad.
That money has become available following the 37 million pound sale of Juan Mata to Manchester United. While the champions are not in the running to retain the title this year, their move for the Spaniard proves that top players can be signed in January, even if clubs have to pay a premium price.
And his switch also strengthens a United side that has faced Chelsea twice already this season but has still to come up against Arsenal and Manchester City a second time. Should the Spaniard prove the difference in those ties, his sale by Chelsea will look all the more like calculated genius.
The likes of Luis Suarez, Nemanja Vidic and Patrice Evra have all been January signings. There will be players available in the final week of the window who could make the difference this season.
One such player is Julian Draxler. Arsenal officials will fly to Germany this week to hold talks over a deal for the Schalke attacker, who has a 45 million euro release clause in his contract.
Arsene Wenger is reluctant to spend more than 36 million euros on the German but the Arsenal manager only has to look at the impact of Mesut Ozil’s arrival last summer to conclude that it could be worth pushing the boat out.
Draxler would be the major signing to strengthen an attack overly reliant on Olivier Giroud and hampered by injuries. While everyone should take Arsenal seriously as a title challenger, signing Draxler could make the difference as it battles against two superior squads in Chelsea and Manchester City.
City looks in need of a central defender as the fixtures pile up and the club fights on four fronts.
The first-half display in Saturday’s FA Cup clash against Watford exposed the backup center back pairing of Joleon Lescott and Martin Demichelis. They need a commanding defender to partner with captain Vincent Kompany - and with Eliaquim Mangala and Nicolas Otamendi long-term targets, who could rule out a last-minute flurry of activity at Eastlands?
In such a closely fought campaign, it could make all the difference.
ROONEY - IS HE REALLY WORTH THE FUSS?
Even Manchester United supporters must have to wonder whether Wayne Rooney is worth all this fuss.
Reports have suggested that the striker has been given access to privileged information over the club’s transfer plans as United attempts to convince him to sign a new 300,000-pound-a-week deal.
This is a player who has twice, very publicly, tried to force an exit from Old Trafford.
You would understand if a number of his teammates resent the special attention he appears to be receiving from David Moyes and club executives.
Rooney can hold United to ransom over contract negotiations, with just 18 months remaining on his current deal. The England international has scored 11 goals in 24 games this season, but he has no right to demand or expect to be the main man, not in a squad that includes Robin van Persie and now Juan Mata.
If the 28-year-old stays at United, he is likely to surpass Sir Bobby Charlton’s record as the club’s all-time record goalscorer with 249 goals. He has so far netted 208 times for the club.
But Rooney’s antagonizing behavior and transparent lack of loyalty means United supporters will rarely utter his name in the same breath as Charlton.