5. lex Grimaldo (Barcelona B)
Alex Grimaldo is the youngest player on this list at 17 - he plays for Barcelona's B team and has already made an appearance for the Spanish U21 side. Having come through the Barcelona youth set-up from the age of 13 onwards, he has the pedigree to develop in to a top quality player. Barcelona would be hesitant to let the youngster go but, with Jordi Alba still only 24, it's going to be a long time before Grimaldo gets a decent opportunity for a prolonged run in the first team and it might be best for his development if he is allowed to leave for a club who can afford him more time on the pitch at the top level over the next few years. If he was to sign for Spurs, he wouldn't be overly costly and would likely be pressing for a first team opportunity within a couple of years. As he would likely be unable to make an immediate impact, he would probably need to be signed alongside another left back, but he'd certainly be one for the not too distant future at White Hart Lane.