John was born in Lachine, Quebec in 1941 and moved to Whitby with his wife Beatrice in 1968. In 1969, John became involved with lacrosse and for over 30 years has been associated with both lacrosse and hockey. A loyal sports writer, Brian Legree, siad of John, "DesRosiers is one of the people who make sports tick in Durham". John has hels positions of coach, trainer, timekeeper, executive member, treasurer, or director of a variety of Durham-based sport associations. In 1993, John was the recipient of the President's Award from the Ontario Lacrosse Association. Over the course of his career, John has received rings from the Junior "B" Ontario and Canadian Lacrosse Championships, 2 Minto Cup rings, and 5 Mann Cup rings.

John extended his talents to hockey as well. John was the Ontario Minor Hockey Development Chairman for 10 years; Treasurer of the Eastern "AAA" Hockey League from 1995 to present; minor hockey rep for the York Simcoe Hockey League fro 10 years; Director, Coach and Timekeeper for the Oshawa Minor Hockey Association for 25 years as well as playing an integral role with the Oshawa Legionnaires for 10 years. From 1981 to 1983, John acted as the Sports and Soccer Chairman for the NASC.

One of John's proudest moments originated from his affliation with the 1980 CBC Junior "A" Minto Cup Championship Lacrosse team. The team that accomplished the impossible!