Hummel is part of the Mariners' Opening Day roster, Daniel Kramer of MLB.com reports.
The 28-year-old Hummel finished spring training with walks across each of his last three plate appearances Sunday and Monday, capping a strong body of work in Cactus League play that included a .275/.420/.675 line across 50 plate appearances. Kramer notes Hummel's versatility -- he's capable of filling in at catcher and the corner outfield spots -- helped seal his spot on the Opening Day roster, although his offensive contributions certainly may have put him over the top.