"I could throw a no-hitter, perfect game and be like, 'All right, cool, whatever,' and go home and it doesn't matter," Kelly said. "I just don't like to get too high or too low. I try to live it even keel."
Kelly has been the glue holding St. Louis' pitching staff together for much of the year. He's been called upon to get crucial outs in middle relief, to eat up innings as a long reliever and to serve as a pseudo-starter when gaps in the schedule called for a spot start. Now, the righty is helping stabilize a rotation reeling from injuries and a murky fifth spot.
Kelly has taken it all in stride, fluidly switching from one role to another, seamlessly sliding into a rotation that boasts the fifth-best ERA in the Majors, all while appearing unfazed by pressure, success and even failure, an approach he says he adopted in his first year of professional ball.
Throughout his three years as the closer for the University of California-Riverside, Kelly's easy-going attitude -- which personifies his Southern California roots -- applied to everything in his life, except baseball. When he stepped onto the mound, he stressed the importance of every outing.
"I was always laid back, but then when it came to baseball, I wasn't," Kelly said. "I thought, 'Maybe if I switched over to just be like that the whole time, [it would have a positive effect].' I try not to get too high over an outing or get too down over an outing."
Transitioning from the college game to the pros, Kelly realized that there would be points in his career where he would struggle. He knew, too, that how he handled those times would help determine how much success followed.
"This game is all about handling failure like water on a duck's back," said Cardinals pitching coach Derek Lilliquist. "He's a fierce competitor. He knows how to pitch, and he's prepared for every situation. He doesn't let the surroundings or the situation affect what he does."
Behind rotation mainstays Adam Wainwright, Lance Lynn and Shelby Miller, the Redbirds have featured a revolving door of names -- a host of injured veterans and rookie hurlers have held down the remaining two spots, but none proved to be a long-term solution. The non-waiver Trade Deadline came and went; the Cards stood pat. They believed the remedy was already on the roster.
By then, Kelly had already been inserted as an interim starter, and although manager Mike Matheny was slow to announce the move as permanent, with win after win, Kelly pitched his way into a lasting stay.
"It hasn't been an easy role for him, but he's handled everything we've given him and he's handled it very well," Matheny said. "I think he just became very comfortable with the fact that he was going to do what he could to help us win, not really think about himself and not think about what would be best for him, but what's best for our club."
With a few mechanical adjustments, the athleticism to stretch out his innings work and a willingness to accept any role, Kelly was a natural fit. Since the start of July, he is 6-0 with a 2.24 ERA in nine starts.
Kelly is also one of only three pitchers -- joining American League Cy Young Award favorite Max Scherzer and National League Rookie of the Year Award candidate Jose Fernandez -- with an ERA under 2.00, no losses and at least five wins since the All-Star break.
With all the hype surrounding the Cardinals' rookie pitching talent, it's easy to forget Kelly isn't far removed from that company himself. At 25 years old and in his first full big league season, he is still evolving.
Upon re-entering the rotation, Kelly made a mechanical adjustment, shortening his stride. He believes that has improved his pitch command.
"He's always had the arm, he just needed time," said catcher Yadier Molina. "Right now, he's getting more time to pitch, he's gaining more confidence. When you have confidence, you can do good things."
Kelly was recruited to UC-Riverside as an outfielder, but within two weeks, he was converted into a pitcher. His college coach, Doug Smith, said Kelly quickly fell in love with the swing and miss, relying on his ability to blow pitches by batters.
Kelly has since stopped relying solely on that arm strength. He's pitching to contact more often and reaping the benefits of getting outs on the ground earlier in counts.
"He was younger and aggressive and the whole deal. He wanted to get after it," Smith said. "He wanted to throw the slider more than I would have wanted him to, because people would miss it. And I think he's evolved to the point where he's perfectly willing to let them beat it into the ground."
Kelly thinks his future is best suited for a starting role, but he isn't fixated on that. He just wants to pitch, content with filling in wherever he's needed.
"That's kind of how our motto is -- somebody goes down, somebody else steps up," Wainwright said. "Joe did it last year, too -- that's nothing new for him. He's a quality pitcher; he deserves to be in the rotation. He's doing a great job."