Los Che's boss has lavished praise on the young striker following his performances in Europe, comparing him to two of the world's finest footballers.
The young striker has been called upon as former Che captain Roberto Soldado's replacement following his sale to Tottenham, and has been carrying out his duties with aplomb so far, scoring in both legs against the Bulgarian champion.
Following his side's progression, coach Pizzi claimed the 20-year-old is only behind Lionel Messi and Cristiano Ronaldo when it comes to natural talent on the pitch.
"It's hard to keep the pace like Alcacer does. Compare him with any other footballer in the world with his talent - only Messi and Cristiano Ronaldo are ahead of him," Pizzi said after the match. "It's priceless to have a player so good at finishing in this kind of form."
The Argentine coach insists he has no preference as to which team his side faces in the last eight following Friday's draw.
"There are plenty of powerful teams in there with storied histories, personally I do not care who we get," he added. "It doesn't matter who we face, every team has their difficulties. [All I know is] there will be four great clashes."