The experienced midfielder is not known as a vocal presence on the field, but Bonucci has said that his teammate "knows how to carry his team through difficult moments".
"Pirlo's a leader - a silent leader, but one who knows how to carry his team through difficult moments," Bonucci told UEFA's official website.
"He showed that in Florence in the round of 16, ensuring that we won the match and progressed. He then also scored an important goal which helped us get past Lyon in the quarter-finals.
"Outside of football, he's a great man and has been one of the world's best midfielders in the history of the game."