He played junior hockey for the Nepean Raiders, Ottawa 67's, and the Toronto Marlboros. Gavin was selected 74th overall by the Toronto Maple Leafs in the 1980 NHL Entry Draft. With the Leafs, Gavin got a reputation as a tough defensive forward and penalty-killer. His high was 12 goals in 1984-85. In 1985, he was traded to the Hartford Whalers for Chris Kotsopoulos. There, he added an offensive dimension to his game and scored a career-high 26 goals in 1985-86. He continued to play for Hartford until he was claimed on waivers by the Minnesota North Stars in 1988.