In 1983–84, Murzyn joined the major junior ranks, playing in the WHL with the Calgary Wranglers for two seasons. After a 31-point rookie campaign in 1983–84, he enjoyed a highly prolific second year with the Wranglers recording 32 goals and 92 points to lead all team defencemen in scoring. Named to the WHL West First All-Star Team, Murzyn was the second-ranked prospect by the NHL Central Scouting Bureau for the 1985 NHL Entry Draft, behind Michigan State Spartans winger Craig Simpson. He was selected fifth overall by the Hartford Whalers at the draft on June 15, 1985.