Because of his scoring ability and great heading skills (he was fairly tall, 6 feet 3 inches) he soon moved to Spain and signed for Real Zaragoza.
[1] Amarilla returned to Real Zaragoza where he gained success by leading the team in scoring in the 1982–83 season, finishing as the second best scorer in La Liga.
Despite playing for a brief period, he established himself as a fan favorite by scoring 21 goals and eventually was chosen as one of the top 100 players in Club America's history.
In that year, he helped the team win the Copa Libertadores, the Supercopa and Recopa Sudamericana by forming the unforgettable feared attacking Olimpia trio along with Gabriel González and Adriano Samaniego.
After Ruiz resigned from the Paraguay national team, Amarilla was named as the interim head coach by the Paraguayan Football Association until the start of 2007, where Gerardo Martino was appointed as the new manager.