That point came in the sixth inning of Wednesday night's 5-1 loss to the Mets. Miller, his Cardinals having just pulled within two runs of New York, fell behind David Wright, 3-1. He threw a fastball over the plate, and Wright did what Wright does with 3-1 fastballs over the plate -- he obliterated it.
Wright drilled his ninth homer of the year, halting any momentum St. Louis might have garnered in the previous half-inning and helping to secure the Mets' win.
Young pitchers often need to be reminded that hitting is hard and that they should stop nibbling. Sometimes even veteran pitchers need to relearn this fundamental concept -- throw your fastball, throw it down in the zone, and watch hitters struggle to do something with it.
But the really special ones, the ones with the ridiculous stuff, sometimes might do well to heed the opposite advice. Sometimes, discretion is the better part of valor. Sometimes, it's OK to walk David Wright.
As Miller discussed the at-bat after the game, the gears were already turning. It appeared that perhaps the youngster was already considering that very viewpoint.
"I'm not trying to give them anything to hit, especially when it's 3-1," Miller said. "But at the same time, I'm trying to throw a strike, because I don't want to walk anybody. That one was just one that ran right over the middle. It was a little up. Simple mistake. It happens. He's just a great hitter. I wish I would have made my pitch there.
"I probably should have really, really, maybe even walked him there. Maybe even throw it down and away. I was just trying to throw a strike. It was a bad mistake."
Miller's stuff is exceptional. His command and control are impressive for a pitcher of his age and experience. His learning process is ongoing. You don't have to stay out of the strike zone entirely. But in a situation like that, it's best to make sure you miss out of the zone rather than in the middle of it.
On Wednesday, too many of his misses were in the hitting area. He threw a first-pitch curveball to Wright in the first inning that had a little too much "get me over" to it, and Wright pounced on it for a rally-starting double. And he hung an 0-1 curveball to Lucas Duda that the lefty slugger destroyed for a solo homer.
Miller threw a lot of strikes on Wednesday, and that's a good thing. But his command within the zone was shaky at times, and that can be very dangerous.
"If you've got stuff, stuff kind of trumps a lot of it," said manager Mike Matheny. "And Shelby's got plus stuff. ... But there are going to be days when you aren't as sharp. It happens to everybody. Those are the days, normally, you've got to fight your way through."
The Cardinals are understandably hesitant to coach much of Miller's aggressiveness out of him. They don't want him fearful. They don't want him unwilling to trust his stuff against any hitter.
That's the line that a young pitcher and a coaching staff must learn to walk. You throw the pitch, it gets hit, you figure out how to throw a better pitch.
"[Wright and Duda are] both power hitters," Miller said. "A hitter wants to get a pitch to hit; they were both perfect pitches for them to hit. It's just not a good job of me executing pitches at certain times, especially in a hitters count. You can't really throw a ball right down the middle."
He's already getting there.