Hopkins underwent a right shoulder labrum repair procedure this week and was placed on the full-season injured list by Double-A Erie on Friday, Evan Woodbery of MLive.com reports.
Hopkins cleared waivers and was outrighted to Triple-A Toledo on Sunday.
Hopkins was designated for assignment by the Tigers on Thursday.
The Tigers claimed Hopkins off waivers from the Giants on Tuesday.
Hopkins was designated for assignment by the Giants on Tuesday, Andrew Baggarly of The Athletic reports.
The Giants acquired Hopkins from the Reds on Tuesday in exchange for a player to be named later or cash considerations.
The Reds designated Hopkins for assignment Thursday.
The Reds optioned Hopkins to Triple-A Louisville on Friday, Charlie Goldsmith of The Cincinnati Enquirer reports.
Hopkins entered Sunday's game after Stuart Fairchild left with a concussion and went 0-for-3 in a 10-3 loss to the Blue Jays.
Hopkins was recalled from Triple-A Louisville on Saturday.