Alvarez was released by the Tigers on Thursday, Evan Woodbery of MLive.com reports.
Alvarez missed all of 2023 while recovering from Tommy John surgery but had re-signed with the Tigers on a minor-league contract last week. It's not clear what happened between then and now, but Alvarez is a free agent again. The 34-year-old holds a career 3.47 ERA over parts of 10 major-league seasons.