While the Cardinals haven't ruled out the possibility of Miller making a September start, his place, for now, is in the bullpen, where he'll be available as soon as he's needed.
"I knew it was always a possibility if I had a good year," Miller said of the callup. "It took a huge turn and I started pitching a lot better. It's just a huge honor. I tried to keep a positive look at it all year, and now I'm here."
For Miller, his big league arrival isn't only the cap to a career-long goal, it's the culmination of a tumultuous Minor League season. Many expected Miller, who is the team's top prospect, to be here much earlier than September. He was the organization's Minor League Pitcher of the Year in 2010 and 2011, and he had not endured much in the way of struggles at any level.
His first taste of Triple-A, though, was, for several reasons, not pleasant. The weight Miller dropped over the winter in an attempt to become fitter cost him velocity. His hesitancy to utilize his offspeed pitches allowed batters to sit on his fastball. He was giving up home runs at an alarming rate.
Through his first 17 starts, Miller had four wins and a 6.17 ERA. The turnaround, though, began around the time of the All-Star break. After it, Miller posted a 7-2 record and 2.88 ERA in 10 starts. He struck out 70 in 59 1/3 innings.
Miller also regained about 10 pounds, which helped him gain back the lost velocity.
"Going on how I started, I didn't know what was going to happen," Miller said. "I could have gotten traded. They could have given up on me. I stayed positive. I turned my season around. I took everything into consideration. Now, I'm here and I'm happy.
"At the same time, I didn't have near the season I wanted to. If I would have thrown better earlier, maybe I could have gotten called up earlier. But now that I'm here, it's a huge relief to know that they were paying attention to my progress."
Miller's biggest adjustment now will be learning how to pitch in relief. All 78 of his Minor League appearances were starts.
"We brought him here to use him," manager Mike Matheny said. "It's not just a gift trip. He pitched very well and he's one of the best arms we have in the system, and we're in a push here, so we need to have our best ready."