Reed was optioned to Triple-A Syracuse after Game 1 of Tuesday's doubleheader against the Cardinals, Deesha Thosar of the New York Daily News reports.
Reed made his season debut in Game 1 and picked up his first big-league win with two scoreless innings, but he won't stick on the active roster for the nightcap. The 29-year-old could rejoin the Mets later in the year as part of the bullpen shuffle.