Andrea Stramaccioni's men have won their last eight games, with the Argentine finding the net on five occasions in 10 games this season, and the Italy international defender is aware of the task at hand.
"I am afraid of Diego Milito," Barzagli told Sky Sport Italia. "He is a complete striker, one of the strongest in Europe. He does not miss a thing."
Inter has climbed all the way to second place in Serie A and trails Juventus by just four points in the race for the Scudetto through 10 matches. Juventus' unbeaten streak in league play stands at 49 and will face perhaps its toughest threat in Turin this weekend, despite Barzagli playing down the significance of the match.
"Inter are a worthy threat," Barzagli said. "Stramaccioni is a good coach, and I think it is right that a young trainer with good ideas is getting a chance. I don't think the match can be considered a crucial one at this stage of the season. The Nerazzurrican definitely challenge for the title, but we are a group that believes in ourselves.
"We always try to keep our feet on the ground and for a lot of us it has been a tough start, what with the Champions League as well. Saying that, I hope that we can go on and dominate."