Harrison, 32, played in just 36 games in his first season with the Tigers because of a hamstring injury. He hit .176 with a home run and 8 RBIs and made 34 starts at second base.
Harrison signed a one-year deal with the Tigers in February, but with Detroit on pace to lose 113 games, general manager Al Avila didn't think the 32-year-old fit into the late-season plans.
"At this stage in the season, it obviously makes sense for us to look at our young guys," Avila said. "We have been happy with Harold Castro and Niko Goodrum and some of our younger guys. We're going to continue that course."
The two-time All-Star played the first eight seasons of his major league career with the Pittsburgh Pirates and has a career batting average of .273 with 53 home runs and 277 RBIs.
The Tigers also released right-hander Sandy Baez on Friday to create room on their 40-man roster for veteran right-hander Edwin Jackson, who will start Friday night's game against the Kansas City Royals.