 In 1943 when the professional football era began in Mexico, CD Oro missed the opportunity to join the league, however other teams in the Guadalajara metropolitan area region such as Club Deportivo Guadalajara, Atlas de Guadalajara did get an invitation that year.CD Oro saw this events as a wake-up call to get an invitation into the professionalism.CD Oro was finally invited to take part of the 1944–45 tournament along with Puebla FC and Club León, both teams had been taking part in other amateur leagues in Mexico.