Miller, 19, was invited to Major League camp this spring and seized the opportunity, showing the Cardinals' staff enough to keep him around far longer than initially intended. On Sunday, he pitched for Team USA at the XM All-Star Futures Game.
It's heady stuff for a kid who wasn't even in pro ball 12 months ago.
"I'm just really soaking it in," Miller said on Sunday morning. "Being around these guys that are a whole lot older than me. ... It kind of reminds me of big league camp this year. I'm just taking advantage of it, seeing what everybody is like. They've got a big league mentality. Everybody, they all have a certain talent here and they're here for a reason. I'm looking forward to meeting all of them and seeing how they are."
The right-hander, selected in the first round of the 2009 First-Year Player Draft, came to Angel Stadium on a roll. He pitched once in a four-week span from late May to late June, taking time off from games in order to refine his mechanics and mitigate his innings load. Miller came out of the break better than ever and has blown hitters away in his past three starts.
In those games, Miller allowed four hits and three walks, striking out 16 in 11 innings. He was on a strict pitch count in the first of the three, and the third was washed out after three innings, explaining the low total. Miller is dealing lately, having benefited from the break.
"When I was throwing my curveball and stuff like that, I wasn't really comfortable throwing it," he said. "Same with my changeup. My mechanics were off on my offspeed. It's all fixed now. That was the main thing. I was throwing bullpens to straighten them out. Just taking a little bit of time off, letting my arm catch up. No [injury]. Really just trying to see what was up and get better."
Since his return, he said, Miller has been throwing a lot more fastballs than before. He has a good one, with easy mid-90s velocity as well as movement. He also finding that his location and command are improving greatly as his first full season goes along.
"It's ridiculous," Miller said. "My fastball is so much better. I can put it wherever I want it. That's my pitch right now. Use it just as much as I did in high school. I throw a little bit of offspeed now and then. The other day I threw five offspeed pitches. I use my fastball a lot, I can locate it, and when it's on, it's on."
He also turned in a respectable, if brief, showing in the Futures Game. Miller allowed an infield hit that was erased on a caught-stealing, and got a ground-ball out before he was lifted.
For a pitcher of Miller's age and experience, though, it's less about what happens on the field at an event like this and more about the whole experience. Once again, he's surrounded by top talent -- players who are going to appear in the big leagues.
"It's a good experience for me at my age," Miller said. "Talking to everybody and seeing what they have to tell me, even as far as telling me what kind of pitches they throw, what grips they use, just seeing what they thought about the game. It just benefits me so much, picking up on what they have to say to me."
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.