DeMarco played his first two professional seasons in the CHL minor league, earning brief NHL callups to New York. In 1971–72, he played with the Rangers full-time, appearing in two thirds of the scheduled games, recording 4 goals and 11 points in 48 games.
DeMarco began his professional career in the CHL minor leagues before making sporadic NHL appearances in New York. In the 1971–72 season, he played a full slate with the Rangers, missing only one third of the scheduled contests, accumulating 4 goals and 11 points over 48 games.