Desjardins was drafted 38th overall in the 1987 NHL Entry Draft by the Montreal Canadiens from the Granby Bisons of the Quebec Major Junior Hockey League (QMJHL). After playing one more season for Granby, he joined the Sherbrooke Canadiens of the American Hockey League (AHL) in time to make his professional debut in the spring of 1988, playing three regular season games and four playoff games. He began his NHL career in 1988–89 with two goals and twelve assists in 36 games. He also played in 14 playoff games on Montreal's way to the 1989 Stanley Cup Finals, a loss against the Calgary Flames.