The Mets optioned Warren to Triple-A Syracuse on Monday.
Warren was the 27th man during Sunday's doubleheader against the Rockies and tossed two scoreless frames in the first contest. He's fared well during his brief time with the big club this season, yielding only one run with a 5:0 K:BB in 3.2 innings, but Warren will report back to Syracuse and wait for another opportunity in the majors.