Miller has struggled with his pitching mechanics and command this season, and it's resulted in two short outings in his last starts. Pitchers usually throw sessions in the bullpen on days when they are not pitching, but the D-backs wanted to try something different with Miller and let him practice his mechanics on the game mound.
"He felt great. He looks good and he feels good," Hale said. "They have video of it, so they'll look at the video."
Jesse Sanchez is a national reporter for MLB.com based in Phoenix. Follow him on Twitter @JesseSanchezMLB and Facebook. This story was not subject to the approval of Major League Baseball or its clubs.