After being drafted O'Sullivan chose to play in the college ranks and played with the Boston University Terriers for 4 years. O'Sullivan missed the majority of his freshman year (1992–1993) after suffering a neck injury during a game versus Boston College.
O'Sullivan, having been drafted, decided to pursue higher education athletics and played with the Boston University Terriers for 4 years. He was unable to participate in most of his freshman year (1992–1993) due to an injury sustained to his neck during a match against Boston College.