Third baseman Bob Aspromonte was one of the original expansion draft picks made by the Colt .45s after the 1961 season. The 23-year-old Brooklyn native soon became a fixture at third, setting a National League record for third baseman in 1962 with 57 consecutive errorless games. In 1964 he batted .280, hit 12 homers and played excellent defense to earn MVP honors for the team.

"Aspro" played through the 1968 season, becoming the last of the original Colt .45s to remain with the franchise. In that season he and Rusty Staub were fined by the team for refusing to play after the assassination of presidential candidate Robert Kennedy. After that season was over, Aspromonte was traded to Atlanta for utility infielder Marty Martinez. Today, he remains third on the team's all-time list with 931 games played at third base.