DeJong has been placed on the full-season injured list at Triple-A Toledo with a leg injury, Evan Woodbery of MLive.com reports.
DeJong was injured May 12 just a week after signing a minor-league deal with the Tigers. The club has not revealed the exact nature of the veteran infielder's injury, but whatever it is was enough to knock him out for the rest of the season. DeJong will be a free agent this winter.