Yellin was an amateur golf champion in New Jersey and was on the United States golf team in the 1965 Maccabiah Games in Israel, winning a silver medal. In the 1960s and 1970s, while living in Florida with his family he was a well known tennis umpire. He was a chair umpire for World Championship Tennis matches played in Hollywood and Aventura, as well as at the WCT finals in Dallas. Jerry also was an umpire at the 1969 US Open (tennis).