I recently came across the first Knoop that played a professional sport [that I’m aware of]. Bobby Knoop [Robert Frank Knoop] was born 18. October, 1938 in Sioux City, Iowa. He played for the Angels, White Sox and Royals between 1964 and 1972. More information about Bobby Knoop can be found here.
Bobby: if you ever read this, it’d be great to hear from you!
../mk