Pacheco (elbow) was claimed off waivers by the Tigers on Tuesday and optioned to Triple-A Toledo.
Pacheco had been placed on outright waivers by the Cardinals earlier this month as he recovered from a bit of elbow tightness. The 24-year-old right-hander posted an encouraging 3.05 ERA with 84 strikeouts in 62 innings last season between Double-A Springfield and Triple-A Memphis. Assuming good health, he could make his MLB debut out of Detroit's bullpen at some point in 2023.