Gsellman will start Wednesday against Washington and will be stretched out as a starter moving forward, Anthony DiComo of MLB.com reports.
The Mets needed another starter after Michael Wacha landed on the injured list with shoulder inflammation Sunday. Gsellman has 29 career big-league starts under his belt, though the last one of those came back in 2017. He has a lifetime 4.60 ERA in 156.2 innings as a starter, slightly worse than his 4.25 mark in 152.1 frames in relief. While the Mets will stretch him out going forward, it's unlikely that he'll be able to pitch particularly deep in Wednesday's contest, given that he threw just a single inning in his lone appearance this season after missing the start of the year with triceps tightness.