5) Rodrigo Mendoza – Elche to Arsenal (£17m)
The Gunners have been heavily linked with the 20-year-old, who has been compared to Barcelona playmaker Pedri.
Mendoza also has a release clause in his contract, which is worth around €20m (£17m).
That means a bid during the January transfer window can’t be ruled out, as there is a danger that teams will make bids and beat the Gunners to the player’s signature.
Manchester City have also been mentioned as potential suitors, along with several other clubs.
