Cunniff signed a minor league contract with the Marlins on Wednesday, Baseball America reports.
Cunniff had a 4.24 ERA through 17 innings last season before he was outrighted by the Braves in November. He's likely to begin the season as organizational depth, provided he makes the team, but injuries to the Marlins' bullpen could force them to call Cunniff up, though he wouldn't likely earn many high-leverage opportunities.