In November of 1987, he was assigned to the faculty of the Saint John Neumann Seminary of the Archdiocese of New York, where he served as Academic Dean and Professor of Fundamental Catholic Theology, from 1987 until 1997. While serving on the seminary faculty, he earned a Doctoral Degree in Theological History from Fordham University in 1992. Father Rossi also served as an Adjunct Professor, in the Department of Philosophy and Religious Studies, at Pace University, in New York, from 1995 to 1999. In that capacity, he taught both comparative religion and the history of philosophy.
In January of 1998, he was appointed pastor of the Parish of Saints Philip and James Church, in the Bronx, a position he held until his appointment, in September of 2008, as pastor of Saint Michael the Archangel Parish, which is also in the Bronx. Father Rossi presently serves as an instructor in the humanities at the College of New Rochelle, in New York.