 Oana spent the 1935 and 1936 seasons with the Syracuse Chiefs of the International League. He hit .300 with 21 doubles, 8 triples, and 12 home runs in 320 at bats during the 1935 season. Oana spent the 1937 season with Knoxville and Little Rock in the Southern Association, but an injury in Little Rock forced him to finish the season playing semipro ball in North Carolina. Oana next spent two years playing for the Jackson Senators in 1938 and 1939. In 1938, he hit .320 with 39 doubles and 26 home runs, and in 1939, he hit .323 with 20 doubles, 12 triples, and a career-high 39 home runs.
