The defender feels the Bianconeri will fall short domestically and in Europe if they fail to address their current problems at the back.
Giorgio Chiellini has stressed that Juventus must improve in defense if the club is to be successful this season.
The Italian champion kept its second clean sheet of the Serie A season in this weekend's 1-0 victory over Torino, but Chiellini feels the team still has plenty of room for improvement at the back.
"We have to improve in certain aspects," the 29-year-old told Corriere dello Sport. "We’ve conceded a few goals this season due to a lack of focus, even if we have managed to win almost all of our games.
"Saying that, against Torino, we ran no risks at all at the back."
The Bianconeri host Galatasaray in the Champions League on Wednesday as they are gunning for their first win in Europe this season after a 1-1 draw against Copenhagen on matchday one.