Defenseman Sean Gagnon prepared himself for the ranks of major junior hockey after playing two years in the NOJHA with both Sudbury and Sault Ste Marie before making the jump to the OHL's Sudbury Wolves in 1991-92. The next year he was bounced around between three teams, the Wolves, the Ottawa 67s and the Sault Ste Marie Greyhounds. Although he provided a steadying influence on the blueline he had not sufficiently impressed NHL scouts to the point where they would draft him. Feeling that he could use another year of development, Gagnon returned to the OHL as an overage player in 1973-74 playing for the Greyhounds.
In 1994-95 he turned pro with the Dayton Bombers. What he lacked in scoring prowess he more than made up with his fisticuffs, spending 339 minutes in the penalty box. His second year in Dayton yielded much the same results, 326 minutes in the sin bin. However, those totals paled in comparison to the 457 minutes he accumulated in 1996-97 with the Fort Wayne Komets of the IHL. Clearly he had established himself as a "policeman" which he felt was his one and only hope of ever reaching the NHL.
In May, 1997 the Phoenix Coyotes inked Gagnon to a free-agent deal and he played in his first five NHL games that year. The next year he played in two more games for the Coyotes, but it was evident he was not going to be part of the team's permanent plans. Gagnon picked up and moved to Finland for the 1999-00 season, playing for Jokerit Helsinki. He returned to North America for the 2000-01 season after signing a deal with the Ottawa Senators, but after just five games with them was traded to the New York Rangers although he has never played for them. In 12 NHL games he has picked up one assist.
In 2001-02 Gagnon played in the AHL with the Hartford Wolf Pack.
