World football is short on quality defenders these days. The old guard of Carles Puyol, John Terry, Rio Ferdinand, Alessandro Nesta, Lucio and others are no longer at the top of their game, and the new generation has not been able to assert its dominance.
Sergio Ramos looked tremendous against Barcelona in this weekend's Clasico, but the horror show he put on against Bayern Munich highlighted his inconsistency. Gerard Pique was once up for consideration as the best center-back in the world, but he hasn't even been able to get games at Barca as of late.
Thiago Silva is generally the center-back considered by most to be the best in the world, but he made some major errors against Arsenal that allowed the Gunners to nearly overtake AC Milan in the Champions League.
Giorgio Chiellini was once regarded as one of the best, but the lack of Champions League football and his constant shifting between left-back and center-back has made it hard for Chiellini to maintain his reputation.
And the list goes on and on. For every defender that is or was once upon a time considered the best or one of the best in the world, there is at least one good reason to doubt the legitimacy of that title.
But there is hope. As the world's top teams continue to bring in new defenders from their youth system, there is always a chance that they will uncover the next Paolo Maldini or Franco Baresi.
And so, with that chance in mind, we lay out eight defenders who we think could become legendary, or at least highly successful, by the end of their careers.
Note: All the players on this list are U-21, since the players above 21 are already established and well-known in the world football community.