#1 Matthijs de Ligt (Ajax)
The way Matthijs de Ligt has begun deliberating over his decision, pondering all possible options and ramifications behind what lies next is frustrating Barcelona: rightly so. They are getting restless and genuinely worried his head, or that of agent Mino Raiola, has been turned towards Ligue 1 champions Paris Saint-Germain or elsewhere, away from Spain.
It speaks volumes for just how good he already is, their defensive situation, and where they have envisioned their future with him and Frenkie de Jong as an integral part of those future plans. A generational player, he's comfortably the best defender in his age group across the world and it's imperative they do all they can to ensure he joins them over PSG and the rest of their European rivals.
He's still only 19 and yet the future is remarkably bright, though Barca's existing defensive options could be seen as a stumbling block: World Cup winner Samuel Umtiti has endured a frustrating campaign after a troublesome knee injury, compatriot Clement Lenglet has stepped up in his absence despite not being the finished article either, while an invaluable Gerard Pique (32) continues to prove his worth despite being on the decline.
They have already invested in young defensive prospects but this is an exception to the rule: de Ligt is something special and one they cannot afford to miss out on this summer.