 After spending 1939 out of organized baseball, Calvert was signed by the Cleveland Indians organization to a contract in 1940, and was invited to spring training.He then spent the season with the Cedar Rapids Raiders of the Illinois–Indiana–Iowa League and the Wilkes-Barre Barons of the Eastern League, playing in 21 total games for the two teams.He spent 1941 with Cedar Rapids, and finished the year with six wins, three losses, and a 2.39 earned run average (ERA) in 11 games.