Career
In 1978, Gantenhammer began his professional indoor career with the Pittsburgh Spirit of the Major Indoor Soccer League. In 1979, he moved to the Houston Summit. In 1980 he moved to the Baltimore Blast for two seasons before spending the 1983-1984 season with the Memphis Americans.
He played the 1984-1985 season with the Columbus Capitals in the American Indoor Soccer Association.
After retiring from playing professionally, Gantenhammer played for the Pan American Airlines Soccer Club. He currently plays for the Las Vegas United Stars.