 He led the 1973 Greenwood Braves of the Western Carolinas League to a 61–66 record, then had a 33–33 record with the 1975 Kingsport Braves of the Appalachian League.He also worked as a minor league pitching coach for the New York Yankees for 22 years.As a coach, Wilhelm said that he did not teach pitchers the knuckleball, believing that people had to be born with a knack for throwing it.