Walker impressed this spring with his velocity and performance in his one Cactus League start, Shannon Drayer of 710 ESPN Seattle reports.
The veteran right-hander signed shortly after spring camp opened and was treated cautiously by the Mariners after undergoing Tommy John surgery and dealing with a sprained shoulder capsule over the last two seasons. Walker was primarily limited to live batting practices and simulated games, but he flashed a mid-90s fastball and struck out Christian Yelich with his new spiked curve during his one spring start against the Brewers. Walker will head into any ramp-up period before the delayed start to the regular season with a seemingly secure grasp on the No. 3 spot in the rotation.