The Mariners designated Zulueta for assignment Wednesday.
Seattle needed to free up a spot on its 40-man roster. Zulueta has spent all of the 2026 season at Triple-A Tacoma, holding a 5.75 ERA and 21:16 K:BB across 20.1 frames. He stands a decent chance of passing through waivers, and if that happens he could remain in the organization.