The Mets optioned Warren to Triple-A Syracuse on Thursday.
After being recalled from Triple-A on April 14, Warren made two appearances out of the bullpen and gave up one earned run on two hits and no walks while striking out four batters in 1.2 innings. The 30-year-old will now return to Syracuse to work as organizational bullpen depth, clearing space on the active roster for Christian Scott, who will start Thursday's game against Minnesota.