Goal runs through the most impressive deals of the window, ranking the players in terms of potential, price, form and the buyer's needs
Getty Images20Luka Jovic: Eintracht Frankfurt to Real Madrid €60m (£55m/$66m)
With one eye on the future, Real Madrid splashed some serious cash to sign Serbian striker Luka Jovic.
At 21, he is certainly a good prospect and scored 17 Bundesliga goals last season for Eintracht Frankfurt.
Jovic is still, however, very raw and has yet to impress for Real, meaning Karim Benzema's starting spot up front is not looking under any threat right now.
AdvertisementGetty Images19Lucas Hernandez: Atletico to Bayern €80m (£72m/$88m)
A World Cup winner with France, Lucas Hernandez swapped Atletico Madrid for Bayern Munich over the summer to reinforce the Bundesliga champions' backline.
While demanding a hefty transfer fee, the 23-year-old still has his best years ahead of him and will play a key role for the Bavarians this season.
Getty18Aaron Wan-Bissaka: Crystal Palace to Man Utd €55m (£50m/$60m)Though hardly cheap for a 21-year-old right-back, Aaron Wan-Bissaka fills a gaping hole in Manchester United's backline and his early performances have shown that he's capable of bringing plenty to Old Trafford, in both attack and defence. Getty17Dani Ceballos: Real Madrid to Arsenal (loan)
The one issue with Dani Ceballos' arrival at the Emirates from an Arsenal perspective is that he has only joined on loan.
The Real Madrid midfielder has already become a firm favourite with Gunners fans, thanks in no small part to the fact that he racked up two assists on his first start, against Burnley.