Amalfitano spent a life in baseball, including one season with the expansion Colt .45s in 1962. He started at second base in the first game in franchise history. He hit .237 with one homer in 137 games.

He was claimed from the Giants in the 1961 expansion draft and traded back to the Giants after the 1962 season for outfielder Manny Mota and pitcher Dick LeMay.

After his playing career ended, Amalfitano spent many years as a coach and manager, including a three-year stint as the manager of the Chicago Cubs (1979-1981).