Duffus was named to the Titan/NCAA East All-America first team in 1992, following a season in which he was named the men's hockey team's most valuable player — a rarity for a sophomore. He started 28 of 29 games that season and compiled a 2.64 goals-against average, which ranked fourth in the country. He was also named to the All-ECAC second team and All-Ivy League first team. He signed a contract with the St. Louis Blues and played professionally for 12 seasons in North America and Europe. He also backstopped the U.S. national team to a bronze medal in the 1996 International Ice Hockey Federation World Championship.