 In 1970, Leeker signed with the St. Louis Stars of the North American Soccer League (NASL).That year, he played in twenty-two games and scored five goals as he was named the NASL Rookie of the Year.On March 19, 1971 Leeker scored the first goal in NASL indoor history in the eighth minute of the opening match of the NASL's "Hoc-Soc" Tournament played at the St. Louis Arena.