Leahy's evolution leading to strong results for Cards

PHILADELPHIA -- The Cardinals once thought so little of reliever Kyle Leahy's future that they passed him through outright waivers -- and thereby exposing him to 29 other MLB teams -- to create a spot on their 40-man roster following the 2023 season.

Leahy went 1-1 with a 4.07 ERA in 33 appearances last season, but the Cards optioned him to Triple-A Memphis five different times.

So, why then, you had to wonder on Monday, was Leahy facing Phillies superstar Bryce Harper in a one-run game with a Citizens Bank Park sellout crowd of 42,513 at full throat? Well, because no Cardinal has made more progress or altered the course of his career more over recent years than the 27-year-old Leahy, a Colorado Mesa product who was the 513th pick in the 2018 MLB Draft.

Throughout Leahy’s often rocky journey, he always had one fervent supporter: Cardinals pitching coach Dusty Blake. It was Blake who boldly predicted in ’23 the right-hander could someday become, “the best arm in our bullpen,” per manager Oliver Marmol.

“I don’t remember exactly what I said or pounding the table, but we were going through guys, and I remember supporting the idea that he could be a big part of what we were doing down the road,” Blake recalled. “One thing that always made him unique was his approach to everything.

“With young guys, you have to almost protect their confidence. This is their dream job and anytime there’s something negative it can affect their confidence. But [Leahy] didn’t have any fear. … He has a growth mindset and that’s something you see a lot of successful people in this game have.”

Back to the critical Leahy showdown against Harper on Monday. Not only did the mild-mannered, soft-spoken Leahy retire Harper, he also tricked him with a back-up slider for a strikeout looking. How about this for growth from Leahy? Lefties are now just 2-for-31 (.065) against him this season.

When looking for reasons why the Cardinals -- a team supposedly in “reset” mode and building for the future -- have become the hottest team in baseball, look no further than an unlikely blossoming standout such as Leahy. Even he is shocked at how far he has come from the days when he was being exposed to waivers and shuttling back and forth to Triple-A.

“There’s moments [when I think about that], but I don’t know if I will ever do that fully until my baseball career is over,” Leahy said following the Cardinals’ ninth straight victory on Monday. “This game can humble you real quick. So, whatever success I’ve had over the past month, the goal is just starting because we have a lot of season left. We’re on a good run and we want to do something this year and play in October and early November. So, there’s still a long way to go.”

The improvement of Leahy might make such an improbable run possible. Through 19 appearances, he is 1-0 with a 1.09 ERA and nine holds. Of the 89 hitters he’s faced, just nine have hits and only three have scored. His 2 1/3-inning outing on Monday was his longest of 2025, and it was the eighth in which he’s recorded at least four outs.

In terms of Breaking Ball Run Value, a statistic compiled by Baseball Savant, his score of 8 is first in all of baseball. In terms of overall Pitching Run Value, his score of 10 ranks in MLB’s 98th percentile. His ground-ball rate (51.7%, 83 percentile) is a big reason why foes have hit just .111 against him.

Again, back to that Harper at-bat from Monday, it should come as little surprise that the Phillies star was guessing as to what pitch might come. Leahy throws six pitches and can land each of them for strikes. Opponents are hitting just .125 off his slider -- a pitch that has gone from the low 80s to the upper 90s in terms of velocity thanks to a grip adjustment suggested by Blake -- and .182 against his changeup. Also, they’ve yet to record a hit against his sweeper (0-for-10), curveball (0-for-9) and sinker (0-for-10). The addition of the sinker, which tails the opposite direction of his four-seamer, has made him even craftier.

Leahy jokes that the hitter couldn’t possibly know what pitch is coming because he has no clue what he’s going to throw. He follows the lead of catcher Pedro Pagés and executes the pitch called. The pitch variety -- mixed with some maturation -- has allowed Leahy to soar.

“Just time has helped,” he said. “Obviously, I haven’t been there and done that for very long, but every day is another day to work on getting more comfortable.”