A native of East Boston, Massachusetts, Merullo played shortstop for the Chicago Cubs for seven years in the major leagues in the 1940s.

He appeared in three games during the 1945 World Series against two-time MVP Hal Newhouser, pitchers Virgil Trucks, Tommy Bridges, and slugger Hank Greenberg of the Detroit Tigers, who defeated the Cubs in seven games in the Series, the last one the Cubs played in until 2016.

[2] After retiring from professional baseball, Merullo was chief scout for the Cubs from 1950–72, signing, among others, relief pitcher Moe Drabowsky.

He left the Cubs in 1973 to join the then-fledgling Major League Baseball Scouting Bureau, where he served until his retirement at the age of 85 in 2003.

On May 30, 2015 in the early morning, Merullo had died, due to complications following a stroke a few weeks prior, aged 98, as announced by the Chicago Cubs.