The Mets recalled Warren from Triple-A Syracuse to serve as the 27th man for Sunday's doubleheader against the Rockies, Anthony DiComo of MLB.com reports.
Warren was demoted to Syracuse on Thursday but will briefly rejoin the big club for the doubleheader. The right-hander has given up an earned run with a 4:0 K:BB across 1.2 frames in his two outings with the Mets this year.