Indeed, Lucio even its just pre-season has looked like a trainwreck in basic sitautions a defender in this level should handle, not outright errors, but all around shaky and slow in decision making. Marrone is a midfielder in defence, he has the opposite problem of what Vidal did when he was CB for us, Marrone doesnt dare to put pressure on nearest player to him or go for the ball much, while Vidal did it way too much for a CB.
And yeah Bocchetti would a solid option for rotation/backup.