Pirlo insists Juventus cannot go into a game of this magnitude lacking character.
The hosts were stunned inside the opening nine minutes when Nicolas N’Koulou broke the deadlock.
Juventus were kept at bay for the vast majority of the game, but found the breakthrough on the 78th minute mark through United States midfielder Weston McKennie, before veteran defender Leonardo Bonucci scored during the dying embers to secure the maximum points for the Serie A champions.
“It’s true, our DNA must remain at the centre of the whole team. At times, games do get messy, we concede after a few minutes and our opponents defend well,” Pirlo said when he was asked if at times Juventus lost the passion and desire to win.
“When you can’t style your way through, you have to find other ways. We do have to move the ball more quickly, as otherwise we give the opposition more time to get back into position, so it’s all the same thing really.
“A side like Juventus absolutely cannot go into a game lacking character, tenacity and hunger. You need the style and good football, but also the determination. You can’t just have one without the other.”
Next up for Juventus is a crucial encounter against La Liga giants Barcelona in the Champions League on Tuesday as both teams seek to finish top of Group G.