The Mets have designated Wilmer Font for assignment in advance of their second-half opening series against the Marlins on Friday night.
Font, who was acquired earlier this season for prospect Neraldo Catalina, was replaced on the 25-man roster by Chris Mazza.
The 29-year-old Mazza was sharp in his only appearance with the Mets this season, which was also his big league debut. In 4.0 innings, Mazza allowed one run on five hits while walking none and striking out two.
Font, 29, had a 4.94 ERA and 1.35 WHIP in 31 innings (three starts, 12 relief appearances) this season for the Mets.