We don't have the surplus talent or prospects to make deals for really good players like Castro yet.
I think Neito will be on this roster. It's my personal prediction that he's a player and that the Nats took a chance because they have 2 other prospect catchers they prefer; but even if I'm wrong about that, it's not that huge a stretch to go from A ball to equaling the offensive production of our incumbent catchers.
Backup infield spots will be interesting this spring. Wonder what they will do with L Garcia...accept that he can't hit and let him play super sub, or send him to AAA and see if he can develop his swing. He doesn't need to hit that well, considering his speed, to be an acceptable 8 or 9 hole hitter (not leadoff, Robin).