It was in the early 1970s that he befriended future "Menudo" creator Edgardo Díaz, who was working in Spain as manager of "La Pandilla". Diaz contacted Herger about having "La Pandilla" go to Puerto Rico to make some recordings and be shown at Herger's show, and Herger accepted. Herger became such a large propulsor of that group in Puerto Rico that he garnered the nickname "The biggest Pandillero" becoming their agent and producing a series of sold-out concerts in Puerto Rico and the Dominican Republic. He also created a TV series with them and filmed two movies: "Operacion Alacran" and "La Pandilla en Apuros".