A right-handed first baseman, Hacker played in the minor leagues for six seasons. In 1995, he was drafted by the Atlanta Braves and joined their farm team in Eugene, Oregon. In 1996, Hacker led the Northwest League in home runs. The following season, he was a first baseman for the Macon Braves, leading the league in batting average, hits, doubles, home runs, and RBIs and earning Most Valuable Player honors. In 1998, Hacker moved to the Minnesota Twins’ farm system, toiling for the Fort Myers Miracle Twins and the Gulf Coast League Twins. In 1999, was named the MVP of the New Britain Rock Cats. He was promoted to Triple A level with the Salt Lake Buzz in the Pacific Coast League.

The Toronto Blue Jays drafted Hacker in 1992 after he graduated from Mehlville High School. At Mehlville, he was Player of the Year and earned All-Metro honors that season. In 1991, he earned All-Conference honors.

In the early 1990s, Steve starred for the Johnny Mac team in the St. Louis Amateur Baseball Association. He made the SLABA All-Star team in 1991 and was the MVP in 1992.

From 1993-95, Hacker was a standout first baseman for Southwest Missouri State University, now known as Missouri State University. He was a freshman All-American there and made the All-Conference team in 1994. The following season, Hacker hit 37 home runs in 58 games to lead the nation, batted .409 and drove in 95 runs, earning Missouri Valley Conference Player of the Year, and he was once again named All-American.

Hacker has been a hitting instructor in the St. Louis area for many years.