He played over 20 years in the National Hockey League, suiting up for the Los Angeles Kings, Washington Capitals, Minnesota North Stars, Pittsburgh Penguins, Toronto Maple Leafs, and Detroit Red Wings.

He was eventually traded to the Washington Capitals for defenceman Brian Engblom and winger Ken Houston early in the 1983–84 season, which did not work out in the Kings' favor long-term because of Murphy's prolonged success in the league.

In addition to the Kings and Capitals, he also suited up for the Minnesota North Stars, Pittsburgh Penguins, Toronto Maple Leafs, and Detroit Red Wings.

His six assists tied teammate Ray Bourque for tops in the tournament among defencemen, which included Mario Lemieux's overtime goal in game 2 of the Final against the Soviet Union.

Finishing his career with 1216 points, Murphy is currently the fifth highest scoring defenceman in NHL history, behind Ray Bourque, Paul Coffey, Al MacInnis and Phil Housley.

However, following the 2005–06 NHL season, Verbeek left the job as broadcaster to become a scout for the Red Wings, and Murphy took over full-time on west coast road trips.

In the 2007–08 season, Murphy began serving as a "Between-the-Benches" reporter for Fox Sports Detroit when Mickey Redmond was broadcasting home games and fill-in for him when he had surgery to remove a tumor on his lung.