Inducted as a truly great player, Sombrotto attended Chaminade High School and Hofstra University, where he was a second team All-American midfielder in 1980. He played on an unprecedented four U.S. Teams, in 1982, 1986, 1990 and 1994. He was named to the All-World Team in 1982.
Beginning in 1981, he played for the Long Island-Hofstra Lacrosse Club, and was selected to the USCLA All-Club team 12 times. He was twice selected USCLA Player of the Year. Beginning in 1987, he played for the Major Indoor Lacrosse League's New York Saints. He received the Hero's Midfielder of the Year award and the Krongard Award. In 1994, he was inducted to the Long Island Metro Chapter Hall of Fame.