He played junior hockey for the Estevan Bruins and the New Westminster Bruins from 1969 to 1972. The Atlanta Flames chose him 50th overall in the 1972 NHL Amateur Draft. Martineau scored 22 goals as a rookie with the Omaha Knights in 1972-73. He returned to the Knights in 1973-74 and made his NHL debut with 4 games for the Flames as well. In his NHL career. Martineau played in 90 games, scoring 6 goals and 10 assists.