It finally happened—Matthew Liberatore has arrived.
After years of potential and flashes of promise, the 25-year-old left-hander has locked down his place in the St. Louis Cardinals’ rotation and emerged as their most reliable starter. Named to the rotation out of spring training, Liberatore didn’t just seize the opportunity—he ran with it.
Through his first five starts of 2025, Liberatore leads all Cardinals starters with a sparkling 3.19 ERA and a dominant 0.97 WHIP. He’s no longer the pitcher who bounced between the bullpen and spot starts. He’s the guy. The frontline starter the Cardinals envisioned when they traded for him back in 2020, giving up Randy Arozarena in the process.
And now, it’s all clicking.
From Bullpen Arm to Rotation Rock
Before this season, nearly 75% of Liberatore’s big league innings came in relief. When he did get a chance to start, the results weren’t pretty—his 6.35 ERA as a starter last year told the story. But this spring, St. Louis made the call: Liberatore was going into the rotation, no more holding back.
“He’s got top-end stuff,” said John Mozeliak on Opening Day. “It was time to let him prove it.”
That gamble paid off. Liberatore delivered four quality starts in his first five outings, and he’s now pitching like someone who belongs at the top of the rotation.
The Slider Revolution
Liberatore made a key adjustment—he leaned into his slider. Over his last three starts, it’s become his main weapon:
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Slider usage in hitters’ counts: up from 15.4% to 29.3%
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Slider whiff rate: spiked from 25.0% to 44.4%
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Fastball/sinker mix: dropped from 59.0% to 39.1%
He added a touch of velocity to the slider without sacrificing much movement, and the pitch has become a nightmare for opposing hitters.
Elite Command, Eye-Popping Numbers
What’s separating Liberatore from the rest of the league? His command. He currently leads MLB in strikeout-to-walk ratio (14.0), far ahead of even veterans like Nathan Eovaldi (12.67). No other pitcher is even close. He also owns the league’s lowest walk rate at just 1.7%.
Hitters are chasing pitches outside the zone, too—his 31.7% chase rate ranks among the best in baseball. According to Baseball Savant, Liberatore is in the top 10% of all pitchers in total run value and off-speed pitch effectiveness.
“He looks locked in,” said manager Oliver Marmol after Liberatore shut down the Brewers with six innings of one-run ball. “He’s preparing better, he’s confident, and it’s translating on the field.”
Strength, Poise, and Sustainability
Liberatore didn’t just show up this season—he showed up ready. Mozeliak noted that the young lefty put in serious work in the offseason, strengthening his body and cleaning up his diet. That effort has allowed him to carry a heavier workload and stay sharp deep into games.
His walk rate has plummeted from 7.8% last season to just 1.7% this year, and his strikeout rate has jumped to 23.1%. But beyond the numbers, what stands out is his poise.
“He’s staying in control, no matter the situation,” Marmol said. “He’s pitching with maturity, handling pressure, and proving he belongs.”
Liberatore’s breakout isn’t theoretical anymore—it’s real. The Cardinals have found their guy.
