July 16 1955
Marouelli's NHL career started on November 2, 1984, and he has been wearing a helmet while refereeing NHL games since the 1996–97 NHL season. Entering the 2007–08 season, Marouelli had officated 1,411 regular season and 179 post-season games.
On November 29, 2008, he officiated his 1,500th game between the Toronto Maple Leafs and Philadelphia Flyers. A pregame ceremony was held for his achievement. Flyers captain Mike Richards presented Marouelli with a team-signed stick, while Maple Leaf Tomáš Kaberle presented a photo of Marouelli signed by the Leafs.
On April 10, 2010, he officiated his last NHL game, between the Toronto Maple Leafs and Montreal Canadiens. At the conclusion of the game both teams showed their appreciation for his long career by shaking his hand.