Preston began his pro career in the World Hockey Association in the 1974-75 season with the Avco World Trophy champion Houston Aeros. He then played three more years with the Aeros before joining the Winnipeg Jets in 1978-79. The Jets won the Avco World Trophy in 1979 (the league's final year) and Rich was named Most Valuable Player of the WHA playoffs. Prior to his NHL career, Preston played for the University of Denver Pioneers.