B.J. was the Kings 1st draft pick in 1973 (he was a teammate of Richard Brodeur on the 1972 Memorial Cup winning Cornwall Royals) but he opted instead to turn pro with the old World Hockey Association, enjoying fine seasons with Indianapolis and Edmonton. When the Oilers joined the NHL in 1979-80, MacDonald found himself playing right wing on Edmontons fabled GMC Line with Wayne Gretzky at centre and Brett Callighen on the left side. He became a Canuck at the trading deadline in 1981 and was with the Vancouver team for its trip to the Stanley Cup finals in 1982. At the conclusion of his playing career, he turned to coaching, first with the Canucks AHL farm club in Fredericton and later with Muskegon of the IHL. Most recently, he coached in Europe, first in Frankfurt, Germany, and then in Merano, Italy. During the 2005-06 season, MacDonald accepted a position with the NHLs Central Scouting Bureau.