Allen signed a minor-league contract with the Mets on Tuesday that includes an invitation to spring training, Tim Britton of The Athletic reports.
The Marlins reassigned Allen to minor-league camp Wednesday, Christina De Nicola of MLB.com reports.
Allen signed a minor-league contract with the Marlins on Thursday.
Allen was traded from Oakland to St. Louis in exchange for Carlos Guarate.
Allen cleared waivers and was outrighted to Triple-A Las Vegas on Wednesday.
Allen was designated for assignment by the Athletics on Monday.
Allen (undisclosed) was reinstated from the COVID-19 injured list Thursday, Martin Gallegos of MLB.com reports.
Allen was placed on the COVID-19 injured list for an undisclosed reason Monday.
Allen (undisclosed) was placed on the restricted list ahead of Friday's series opener at Toronto, Matt Kawahara of the San Francisco Chronicle reports.