Without Ronaldo, Juventus lacked a cutting edge in attack as Paulo Dybala was unable to really impose himself on the game. Pirlo's men took the lead through Alvaro Morata after the Spaniard was set up by an excellent pass from Federico Chiesa.
However, just before half-time, Gaetano Letizia struck for Filippo Inzaghi's side and ensured that Juventus had to do it all over again.
After the game, Pirlo was asked about his decision to rest Ronaldo for this game. The Italian said that the Portuguese superstar had a minor injury, despite which he had played in the UEFA Champions League win over Ferencvaros in midweek.
The Juventus boss told Sky Italia, via Goal:
"He had a slight problem midweek and wanted to play in the Champions League anyway."
"After international duty, it was natural he’d need some rest. Ronaldo is an added value, but we must try to play our game even in his absence."
"It happens when you have a lot of players on international duty and also play the Champions League. We’re hardly the only club in this situation."
To make matters worse for Pirlo, he will be unable to call on the services of Morata in the Turin Derby next weekend. The Spanish striker was sent off after the final whistle for an argument with the match officials.
Juventus boss Pirlo bemoans lack of composure
Speaking about the game itself, Pirlo said that he wanted his side to show more composure in crucial moments of the match. He said:
"We controlled the first half, had the chances to kill off the game, but still haven’t worked out how to read the various moments of the match."
"We had a corner and took it quickly on the stroke of half-time, but we should’ve controlled the situation and held out until the break. It’s not the first time we have conceded just before the break.
"At the end, we got a bit chaotic and lost our cool, we didn’t manage to turn the chances into goals."
Juventus next face Dynamo Kyiv in the Champions League on Wednesday night.