Although all starting pitchers for the Arizona Diamondbacks have at one least one big question mark heading into the spring, Zack Greinke, Robbie Ray, Shelby Miller, and Taijuan Walker all seem like locks to start the season in the starting rotation.
Greinke needs to prove he is the 200 million dollar ace the D-Backs signed last December. Ray needs to cut down on walks. Miller needs to figure out how to miss bats again. And Walker needs to limit extra base hits especially home runs. That now leaves Patrick Corbin, Braden Shipley, and Archie Bradley to duke it out in Spring Training.