Moreno appeared in 73 games played in Major League Baseball for the Washington Senators from 1950–1953.

After joining professional baseball, Moreno was a star hurler for the Havana Cubanos of the Class B Florida International League, winning 50 of 66 decisions (.758) from 1947 to 1950,[2] before being called up by the Senators for the final month of the 1950 campaign.

In his Major League debut on September 8, he started against the Philadelphia Athletics and pitched a complete game, 10–4 victory at Griffith Stadium.

[3] Moreno spent the full 1951 and 1952 seasons with Washington, as both a starter and relief pitcher, and was credited with 12 complete games and two saves during that period.

[1] As a Major Leaguer, Moreno surrendered 349 hits and 157 bases on balls, and recorded 119 strikeouts, in 336⅔ innings pitched.