Born in Cleveland, Ohio, he was the son of Hal Trosky Sr., the Indians' slugging first baseman who played 11 seasons in the major leagues.

Hal Jr. threw and batted right-handed, stood 6 feet 3 inches (1.91 m) tall and weighed 205 pounds (93 kg).

Trosky grew up in Iowa, his father's native state, and signed with the White Sox as a first baseman in 1954 after graduating from St. Patrick's High School in Cedar Rapids.

Trosky then allowed three runs (with one unearned) to the Athletics in the sixth, and departed the contest with the White Sox still leading at 6–4.

His minor league career ended in 1960 after seven seasons, and Trosky returned to Cedar Rapids, where he spent fifty years in the insurance field.