It was by far Miller's best outing of the year, and it came in his first start since May 24 against the Pirates. The day after that start he was placed on the disabled list with a sprained right index finger.
"Exciting to see," D-backs manager Chip Hale said.
Excitement, yes, but relief was also an emotion that no doubt was felt by both the front office and Miller himself.
The 25-year-old had been at a loss to explain why 2016 had been such a struggle for him. He entered Monday's game with a 7.09 ERA, and at one point, his mechanics were so out of whack that he hit his pitching hand on the mound during his follow-through in an April start.
"I know earlier I've kind of been doing some damage to myself and obviously the team, walking guys and letting guys get on and just not finishing the job," Miller said. "So it was nice to go out there and make quality pitches and go deeper into the game."
The 6 2/3 innings marked the first time Miller recorded an out in the seventh inning this season.
During his stint on the disabled list, Miller worked on his mechanics, and more than anything, the time away gave him a chance to clear his head. After all, what the D-backs had given up to get him and the high expectations there were for both Miller and the team, a slow start only ratcheted up the pressure.
"I thought his stuff was better," Hale said. "I think he trusted it, he threw strikes with it. When the leadoff guy got on, for example, he didn't compound it with walks and then load the bases and stuff that he had done earlier in the year. The velocity has obviously gotten better and better since the first day of Spring Training. That's a very good sign for me."
Miller touched 97 mph on the radar gun and regularly hit 95-96 mph. When a pitcher is throwing that hard he is able to get away with more mistakes with his offspeed stuff, because hitters are worried about catching up to the fastball.
"Velocity felt good," Miller said. "I felt like I was back with that. Everything we've kind of been working on helped get that back to normal. I really can't pinpoint why I felt like my velo is back up, but it's nice to have that. Anytime you're throwing a little harder it takes guys off your offspeed a little bit. It was just nice to go out and pitch a quality game."
Steve Gilbert has covered the D-backs for MLB.com since 2001. Follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.