The Tigers selected Callahan's contract from Triple-A Toledo on Sunday. He'll start in left field and bat seventh in the series finale versus the White Sox.
Trei Cruz was designated for assignment in a corresponding move. The 24-year-old Callahan opened the season at Double-A Erie and posted an .879 OPS in 59 games to earn a bump up to Triple-A, where he slashed .271/.351/.338 with one home run and nine steals across 151 plate appearances and saw time at all three outfield spots. He could get a look in a semi-regular role until the banged-up Tigers get healthier.