Manager Torey Lovullo reported Thursday that Walker will start Game 1 of the NLDS against the Dodgers on Friday.
With Zack Greinke starting the team's wild-card contest Wednesday and Robbie Ray pitching in relief, the Diamondbacks will call upon Walker to open up the best-of-five series against their divisional foes. The 25-year-old posted a solid 3.49 ERA over 28 starts during the regular season. More importantly, he allowed only six runs over 16.2 innings (3.24 ERA) in his three starts against the Dodgers.