Juve were beaten 2-1 by Napoli at the Maradona, with Rasmus Hojlund's double proving too much for the Bianconeri, despite Kenan Yildiz's effort.
Reflecting on Juve's performance, Tacchinardi snapped on Canale 5: "Juve can't seem to raise their leve.
"It was a bad match. A very defensive-minded team without any strikers, Napoli dominated in the first half. In the second half, with a real striker on the pitch, Juve improved even without doing anything special."
He continued: "This is a Yildiz-dependent team.
"Has Juve improved under Luciano Spalletti? No. Has it grown? No. And in my opinion, it's still worrying that they don't bring home any ideas in their dirty matches."