Polanco (knee) will start at designated hitter Monday against the Guardians in his Cactus League debut, Shannon Drayer of SeattleSports.com reports.
Polanco underwent surgery last October to repair the patellar tendon of his left knee. While he hasn't had any known restrictions in Mariners camp, the club has held him out of Cactus League play until now, a tactic that isn't atypical for veteran players. Polanco is slated to be the Mariners' everyday third baseman this season.