The Marlins have designated Joe Thurston for assignment, according to Joe Capozzi of the Palm Beach Post (via Twitter). The move was made in order to make room on the roster for the newly acquired Alfredo Amezaga.
Thurston was just recently promoted to the Marlins' big league roster and started at second base against the Cardinals last night. The 31-year-old was impressive at the Triple-A level this year, hitting .315/.401/.477 with nine homers in 104 games.