Muckenhirn was reassigned to minor-league camp by the Mets on Saturday.
Muckenhirn was believed to have a chance to win one of the final spots in the bullpen for the Mets, but instead the southpaw will likely start the 2023 season with Triple-A Syracuse. If Muckenhirn pitches well in the International League, he could be an option for New York by the end of the 2023 campaign.