Castonzo has the potential to develop into a top left tackle capable of shutting down top speed rushers. Started his first game as a true freshman and didn’t leave the field during his four years at BC. He has very good mobility. Masks his lack of strength, to a certain extent, with quickness and positioning. Would be a good fit in a zone-blocking scheme or on a club that loves the screen game. Will probably never be a favorable matchup when facing bigger, more powerful NFL defensive lineman. Still, Castonzo is a first rounder with a chance to be the first O-lineman taken.