Following his stint in the AHL, Virtanen was invited to participate in the Canucks 2015 training camp prior to the 2015–16 season. He impressed during the camp by recording two goals and two assists in six pre-season games and was subsequently named to their opening night roster. His NHL debut came days later when he was subbed in as a replacement for Jared McCann on October 13 prior to the Canucks contest with the Los Angeles Kings. He went scoreless in his debut but later recording his first NHL point (an assist) on a Derek Dorsett goal in a 5–1 win against the Montreal Canadiens. On November 1, 2015, it was announced Virtanen and McCann had made the Canucks' team past their nine-game "tryout" period which would have sent them back to juniors without wasting a year of their contract. Following this decision, Virtanen, playing alongside Brandon Sutter, scored his first career NHL goal in a 3–1 win over the Philadelphia Flyers. After recording one goal and four points in 19 games with the Canucks, he was reassigned to the Comets on a condition stint. He played two games with the team before being loaned to the Canadian national junior team for the 2016 World Junior Ice Hockey Championships (WJC). During the WJC, Virtanen recorded one point in five games and took three penalties in the quarterfinal game against Finland. He responded to his online hate from fans saying, "I was more disappointed in losing the game. We went over there to win a gold medal and we didn't get it. Obviously I want to take a little bit of the responsibility for that." Upon returning to North America, Virtanen re-joined the Canucks and ended his rookie season with 13 points in 55 games.