With just over a day left in the January transfer window, several clubs have been busy.
Here could be five of the best deals made this January.
This could the signing that sparks the revival at Old Trafford, with one of the Premier League's best players in recent years being effectively shown the door at Chelsea by Jose Mourinho. Mata has a World Cup and European Championship winners' medal with Spain, and the 25-year-old is just the sort of top-quality player that United have been sorely lacking in midfield.
Luuk De Jong (Borussia Moenchengladbach to Newcastle, loan)
Newcastle have long had eyes on Holland international striker De Jong, who flourished under Steve McClaren at FC Twente - including scoring 32 goals in one season - but whose career stalled after a big money move to Bundesliga side Borussia Moenchengladbach. He is still young at 23, and if Alan Pardew can restore his confidence then he could be a steal.
Lacina Traore (Monaco to Everton, loan)
The 'gentle giant', all 6ft 8in of him, chose Everton over West Ham after Monaco offered him out on loan. Though the Ivory Coast striker is only 23, he made a name for himself as one of the best strikers in the Russian Premier League with Kuban Krasnodar and Anzhi Makhachkala. Everton fans will also like the fact he has scored a winner against Liverpool in the past.
Mohamed Salah (Basle to Chelsea, £11million).
Goal-scoring winger who tormented Chelsea in the three matches he played against them for Basle. The fleet-footed Egyptian international scored in all three games, and impressed Jose Mourinho so much he used some of the income from Mata's sale to buy him. Chelsea players have likened his style to that of Arjen Robben.
Shane Long (West Brom to Hull, £6.5million)
If you are a club with ambitions of a secure but unflashy mid-table spot in the Premier League, then Shane Long is your man. Hard-working, nimble, and - given the ammunition - a clinical finisher, Hull's move for Long proved the Tigers will spend big to remain in the Premier League's jungle.