Morin (elbow) was reinstated from the 45-day injured list and outrighted to Triple-A New Orleans on Thursday.
Morin (elbow) was transferred to the 45-day injured list Tuesday.
Morin was placed on the 10-day injured list with a UCL injury in his right elbow Friday.
Morin was removed from Wednesday's game against the Blue Jays with a right elbow injury.
Morin (1-0) earned the win Thursday against the Orioles after pitching two scoreless innings off the bullpen.
Morin was claimed off waivers by the Marlins on Tuesday, Jon Heyman of MLB Network reports.
Morin was designated for assignment Sunday, Adam McCalvy of MLB.com reports.
Morin will open the season on the Brewers' 30-man roster.
Morin was invited to the Brewers' big-league camp Wednesday.
Morin refused an outright assignment to the minors Monday and became a free agent.