Willy Lagrilliere played for the General Motors and Spartans teams in Belgium. He won Bronze with the Belgian national team in the 1977 European Championship. He was the starting third baseman for Belgium in the 1978 Amateur World Series, their first Amateur World Series. He hit .217/.217/.217 with no runs or RBI in eight games, while stealing one base in his only try. He fielded .893 at the hot corner. He was a bright spot on a team that hit .126/.193/.146, and his five hits tied Robert Van Lent for 2nd on the squad, one behind Erik Hemmerechts. He was the team's second-oldest player, 3 years younger than Marcel Vogels.