Mascherano did well when he was called upon but i don't think he's a suitable long term option, he still needs to work on his positioning as a defender, was caught in no mans land on quite a few occasions last season. Busquets at CB? no thanks. I think Puyol and Abidal still have a couple of years left and Adriano did very well as the season went on, and I think he will just get better if he gets more playing time. I think last season we were unlucky with the Puyol injury and Abidal's freak tumor, otherwise we're OK for a couple more seasons IMO.
I like our youth prospects but it's a case of how much Pep trusts them. If he isn't going to give them games as they aren't ready, we need proper cover for Puyi and Pique. Abi can slot in there nicely as shown last season, but we don't want to be relying on Masch all the time top drop in there, he's a makeshift CB at the end of the day.
with all the good young defensive prospects coming through, i dont think we should sign a defender, maybe if maxwell leaves, ansaldi or the likes who can play right/left back, has pace, and can defend.