Up to this point, Rossi had been jointly owned by Vicenza and Juventus. When the two clubs were called to settle the property, Lanerossi offered the shocking sum of 2.612 billion lire for Rossi, who became the world's most expensive player, and Italy's most costly sportsman ever at that point. After the 1978 World Cup, during the 1978–79 season, Rossi made his European debut with Vicenza in the UEFA Cup, however, despite scoring 15 goals for the club in Serie A, his season was marked by injuries, and Vicenza was relegated to Serie B. Rossi was subsequently loaned to Perugia, in order to play in Serie A the following season.