Liverpool won their sixth European Cup on Saturday with a 2-0 victory over Tottenham in Madrid.
Mo Salah netted a penalty within two minutes before second-half substitute Origi scored just before full-time to secure the trophy.
The Belgian became the latest in a list of unlikely Liverpool heroes, but Pirlo was unimpressed with both him and the beaten finalists.
“Origi? He came in badly, if he hadn’t have scored, he would have been beaten,” he told Sky Italia.
“His was not a Champions League final attitude, I really didn’t like it.
“The match was also won by these fans, they made a difference.
“Tottenham had no personality, people like Alli and Eriksen who didn’t want the ball. There was little quality in midfield.
“Liverpool deserved the victory for the season they have had but also for these supporters.”