Per Wiki, he started out his football career as a midfielder. I guess he sucked so bad that he moved to the backline because he's big and can bully attackers. Allegri was like 'you used to be a midfielder? OK I let you roam around the pitch, do whatever you want to do, defend, attack, ...I just want big and grinta players with individual brilliance. I used to train Mandzukic, you know'.