What does blocked by a major leaguer mean? You could make a case that every minor league player is blocked by a major leaguer. As of last Fall Cozart represented as weak a spot as we had in the starting lineup. There was much debate as to whether he was a starting SS in the big leagues.
Didi is much more athletic than Cozart, younger and hits LH (a plus). I don't think there's any debating that he was the more valuable player. If he wasn't then AR would have taken Cozart in the deal. The argument here is you have to give up something in order to get something