[2] Johnson was signed by the Toronto Maple Leafs following his junior career and spent five seasons with their Central Hockey League (CHL) affiliate, the Tulsa Oilers.

He was twice a CHL All-Star and was league MVP in 1970, but only managed to earn a single game with the Leafs in the 1969–70 season.

He struggled to find his offensive touch and finished the 1971–72 season with just 3 goals and 11 points in 54 games between Detroit and Vancouver.

In 1972, Johnson jumped to the fledgling WHA, signing with a Winnipeg Jets team featuring superstar Bobby Hull.

In 1972–73, he recorded 19 goals and 42 points en route to helping the Jets to the inaugural Avco Cup Finals.