3) Juan Cuadrado (Fiorentina)
The player most ideally suited to playing as a right-sided wing-back in Louis van Gaal’s 3-5-2 system, it is hard to understand why United failed to complete a move for superb Fiorentina winger Juan Cuadrado. The Colombian international was one of the best wide-players in Europe last season and also attracted strong interest from Barcelona this summer, though their interest cooled towards the end of the transfer window as they instead opted to sign Brazilian youngster Douglas in that position. With van Gaal seemingly set on playing his current five-man midfield, Cuadrado looks to be the final cog in the machine missing from this setup.