I will be beyond pissed off if MON let's L. Young leave, he's a fantastic player. Other than the game against Chelsea, when the whole team were as bad as each other, I don't think I've ever seen him have a bad game for us.
Sure Cuellar is a better defender and adds height at set plays, but being a right back is more than just sticking a foot in, heading something away and hoofing it straight out of play. If MON is letting him go then I hope to god he's got a good replacement lined up.