Massimiliano Allegri has confessed his concern with Juventus' backline as they gear up for another Serie A title defence.
The Italian champions conceded just 20 goals on their way to winning the league last season and have been lauded for their stingy defending in recent years.
However, having allowed their opponents to net in each of their pre-season games, including a 3-2 win at West Ham on Sunday, Allegri wants to see some improvement from Juve.
"It was pleasing to see three of the frontmen get on the scoresheet this afternoon," he said, in quotes reported by Juve's official website.
"In Paulo Dybala, Mario Mandzukic, Simone Zaza and Gonzalo Higuain, we boast four top-class strikers plus there's Marko Pjaca, who can play both as a forward and a midfielder.
"One aspect of our game, however, that we need to put right between now and the start of the campaign is that of tightening up at the back, as we have now conceded in all four of our pre-season friendlies."
Juve have recruited Medhi Benatia from Bayern Munich this off-season to complement Italy's Euro 2016 trio of Andrea Barzagli, Leonardo Bonucci and Giorgio Chiellini.
They still have friendlies against Espanyol and Cologne to come next weekend, before kicking off their Serie A campaign against Fiorentina the following Saturday.