Ion Nunweiller was a football defender, who came from a family with six brothers who were footballers. He played with Dinamo Bucareşti, helping them win Romanian League titles in 1962-65 and 1971. He also led them to Romanian Cup titles in 1959, 1964, and 1968. Nunweiler then moved to Turkey and played for Fenerbahçe in the Turkish League, helping them win the Turkish League title and TSYD Cup in 1970. Nunweiler then became a manager, leading Dinamo Bucareşti to Romanian League titles in 1973, 1975, and 1977.