Walker (9-3) allowed eight runs on seven hits while taking the loss against Atlanta on Friday. He pitched one inning and failed to record a strikeout.
Walker yielded four runs in the first inning, including a three-run shot by Eddie Rosario. The 29-year-old righty then coughed up a solo homer to Michael Harris to begin the second and was later charged with three more runs, two of which scored with Trevor Williams on the mound. Walker's ERA jumped from 2.79 to 3.45 through 104.1 frames after Friday's ugly outing. He also broke his streak of nine starts allowing fewer than four runs. Walker is lined up to face the Reds at home next week.