Juventus' success usually is built on a strong defense and with what Thiago Motta did in Bologna with foundation of success from their defense system, I believe that Juventus will have better defense system in this season. Early matches in Serie A give us some signals of their strong defense system that needs to be tested more by more teams in Serie A.
In the clean-sheet list, there is Miles Svilar from Roma. He is a young and talented goalkeeper and has very promising career. The defense system of Roma is not good and it's their club tradition too so Svilar will not be able to compete for the best clean-sheet against other goalkeepers in Serie A if he continues his career with Roma.
Juventus has been successful because of their strong defense. Now that Thiago Motta is in charge I think they will keep playing tough defense. Motta did well defending at Bologna and Juventus will benefit from his experience. Early games in Serie A show Juventus defense is solid but harder games are coming. Meanwhile Roma young goalkeeper Miles Svilar is talented but Roma defense lets in too many goals. Last season Roma allowed 54 goals the most among top teams. Svilar can not reach his full potential unless Roma improves its defense or he joins a better defensive team.