 He was selected fourth overall by the Vancouver Canucks in the 1978 NHL Entry Draft.As a rookie with the Canucks in 1978–79, Derlago badly injured his knee and was limited to just 9 games, though he did score 8 points.Though he played well in Vancouver, he was unable to live up to team expectations, and was traded to Toronto along with Rick Vaive for Tiger Williams and Jerry Butler on February 18, 1980.