13. Srdjan Babic
Team: Real San Sebastian (On loan at Red Star)
Release Clause: £9.5m
You won't be able to bring him in immediately, as he's on loan at Red Star, with a fee agreed for a potential future move, but he won't necessarily sign for the club at the end of his temporary deal, and keeping an eye on him is a smart move.
The Serbian stopper is only valued at just under £900k, but he's a great prospect at centre-half, and the £9.5m it would take to activate his release will be paid back in performances pretty quickly. Just hope that he doesn't do too well at Red Star in that first season.