Haag began his journalism career in print as an education reporter and editor for "The Dallas Morning News" during the late 1950s. He then moved to radio as news director at WBAP in Dallas before finding his true niche in television. Haag served first as national assignment editor and overnight manager at NBC News, then worked as an assistant news director at CBS News in New York City before joining a then ratings-impaired WFAA in 1973, becoming their executive news director.