 In the spring of 1947, Marrero, as part of a Cuban all-star team, had a chance to pitch against major league teams that were playing in Havana during spring training.He beat the New York Yankees in a rain-shortened 7-inning game, allowing one run and four hits.A week later (now pitching for the minor league Havana Cubans), he suffered a tough 1–0 loss against the Brooklyn Dodgers, allowing four hits and striking out eight.