Sterner played 16 games for the St. Paul Rangers of the Central Professional Hockey League / CPHL, scoring 12 goals and 21 points.

In the 2 months in the CPHL, Sterner had adjusted, made tremendous strides, and was promoted to the Baltimore Clippers of the American Hockey League / AHL. Sterner played well in Baltimore, and early in the new year he was called up to the New York Rangers to play in the NHL.

Sterner made his NHL debut on January 27, 1965 vs Boston Bruins at Madison Square Garden. He then played on January 30 vs Montreal, January 31 vs Detroit and February 3 vs Chicago.

Sterner played in only those 4 NHL games without registering a point or penalty before being returned to the minors. The Bruins, Canadiens, Red Wings and Black Hawks had played physically against him, and he refused to play a similar style. He was equally reluctant to instigate physical play.

Sterner's debut for the New York Rangers in 1965 made him the 1st player who was born and trained in Europe to play in an NHL game.

During his career in the AHL he posted very good statistics - 18 goals and 44 points in 52 regular season games.