The Mets optioned Warren to Triple-A Syracuse on Friday, Anthony DiComo of MLB.com reports.
Warren made four appearances in the Grapefruit League, allowing one run on three hits with a 2:2 K:BB over four innings. The right-hander gave up just one run across 9.1 frames with the Mets last year and could join the big club as bullpen depth at some point this season.