The Cardinals entered the season with two “sure things” in Matthew Liberatore and Michael McGreevy, two projects in Dustin May and Kyle Leahy, and a bounceback candidate in Andre Pallante. I think May and Leahy have gone about as well as could be expected. I don’t need to make the case for May, who had a rough first two starts but has been great since. Leahy has been a mixed bag, but I was never particularly high on him as a starting pitcher, and he’s honestly pitched better than I expected. Yes, he has third time through the order problems, but the last time he was a starting pitcher, he was 25 in AA and very bad there. A 4.25 ERA exceeds my expectations. Pallante is as frustrating as ever, but still looks like he belongs in an MLB rotation with his results. And McGreevy has been about as good as could be expected.
Which leaves the big disappointment, Matthew Liberatore. He was supposed to be the ace, and to be fair to him, McGreevy is outpitching any reasonable expectation one would have for Liberatore, so even if things were clicking for him, you probably still don’t call him the ace. And yet he had a legitimate case as the worst performing starting pitcher for a stretch this season. A stretch that seems to have ended thankfully.
There was not a lot of reason for optimism after Liberatore’s April. Liberatore wasn’t missing bats, which wasn’t a new thing, but he missed even less bats than he did in his 2025 season. He wasn’t getting groundballs, but again he wasn’t really doing that last year either. What he specialized in last year, that allowed him to be an essentially average pitcher, was that he didn’t walk a lot of guys. He had a 6.2 BB%. While his walk rate was a still reasonable 8.1% in April, that is too high for the pitcher he is.
In those first six starts, he allowed one earned run in three of them. But he didn’t really look good doing it. In his first two starts, he allowed a combined 10 hits and 3 walks while striking out just 4 batters. The only runs he gave up were two solo shots, which means he had a 100% left on base rate (the average is 75%, anything above 80% is legitimately pure luck, especially for a pitcher like Liberatore). He allowed at least four runs in his other three starts, which included allowing three homers to the Mariners on April 25th.
Things looked really bleak with the Dodgers next up on the schedule. And then… he had a good start against the Dodgers. Nothing crazy. He pitched into the sixth inning and his only real hiccup was that he walked his only two batters of the game in that 6th inning, needing to be taken out before he could complete the inning. Against the Padres in his next start, he was giving out too many free passes, but he struck out 6 and 58% of balls in play were hit on the ground, so his stuff was certainly working.
And then Liberatore got plagued by the big inning. He had three consecutive starts where he looked good except for one inning. And he was not able to limit the damage in that one inning. Against the Athletics, it was the grand slam to Nick Kurtz in the 5th inning, which were all four of his earned runs that game. Against the Pirates, it was also the 5th and it was a mixture of singles and walks. But he had struck out 8 coming into that inning. And against the Brewers, he switched it up and allowed a three-run homer in the 1st inning.
This to me is a much better starting place than where he was in April. The earned run results ended up being the same (not counting yesterday’s game), but he was broadly pitching poorly for most of the game in April and hoping balls found gloves. Now he was just pitching poorly in one inning, and some of it is just poor sequencing more than poor pitching. Last night, he did not have a big inning go against him, and not wanting to tempt fate and having a starting pitcher in the bullpen, Oliver Marmol chose to take him out in the 6th once the platoon matchup didn’t favor him.
So very quietly, mostly because the earned runs results have not really been in his favor, Liberatore is back to being interesting. In his last six starts of the season, Liberatore has a 3.98 ERA with a 2.62 FIP and 2.96 xFIP. Suddenly, his xFIP is actually lower than last season, mostly thanks to striking out more batters. A 10 strikeout game and a 9 strikeout game in a 11 game sample will tend to do that.
What has changed? Some of it is quality of competition, and more specifically, quality of competition against left-handed pitchers. It doesn’t explain it all by any means though. He faced three of the top 8 offenses against LHP in his first six games (Guardians, Nats, and Astros), and two of those games resulted in 4 ER. In his most recent six game sample, he has faced two of the five worst offenses against LHP (Brewers and Padres), and another two teams who were in the bottom half of the league (Pirates and Athletics). But he also allowed five runs to the Mariners, who have been awful against LHP, and he pitched well against both the Cubs and Dodgers, also in the top 8 offenses against LHP this season.
More specifically though, he has really leaned on the curveball. In his first three starts, he threw his curve 10.5% of the time or less in every start. It became his third most used pitch against the Astros, but then he abandoned it against the Mariners, throwing it just 6% of the time. He used to more against the Dodgers, but the real trend started against the Padres. His curve was still his third most used pitch, but it jumped ahead of the slider at 19.5% usage. Then he used it 21.4% of the time against the Athletics. It was his most used pitch against the Pirates at 23.4%. It went down to 19% against the Brewers, although that was good enough for second most used pitch. He threw one less curve than his fastball against the Cubs yesterday with a season high 30.6% usage rate.
When you up your usage rate of one pitch, another pitch inevitably will be sacrificed and in this case, it’s his slider. He has thrown his slider 24% of the time this season. He hasn’t throw it that often in a game since he did it against the Dodgers. Every game since has been under 24% usage rate. Despite the fact that his slider generates more whiffs, hitters are teeing off if they do make contact. Six of his 10 homers allowed have been off the slider. 15.4% of his sliders produce a barrel, which is actually worse than his fastball, which nobody really considers a very good pitch. The average exit velocity off the slider is 90.4 mph.
I’m sure he’s working on getting his slider back to last year’s rate, when hitters barreled just 6.5% of his sliders and he allowed two homers all year, but in the meantime, his curve has seemingly replaced his slider’s role. His curve is generating tons of groundballs, with 55.6% of balls hit into play off the curve being on the ground. The average exit velocity on his curve is just 83.7 mph. All of this data by the way is not including yesterday’s game. I would be surprised if including yesterday significantly changes things considering the increased usage of the curve though.
One more note: I find it interesting that last season, Liberatore was a six-pitch pitcher, throwing six different pitches at least 10% of the time. That has not really been the case this year. He has nearly abandoned his cutter, which he is only throwing 4% of the time. Might be for the best. It has resulted in a .500 average, and last season it was a .356 average. The cutter isn’t really working. He has also lowered his sinker usage to below 10%, probably in response to the 94.9 mph average exit velocity. It wasn’t a great pitch last year either.
Here’s some reason for optimism. His changeup is getting worse results than last year, but it might be a better pitch. Or he might be using it better. Last year, hitters hit .183 off his change, but barreled 14.9% of them and produced a whiff just 7.8% of the time. This year, hitters are batting .297 off his change, but he’s getting a whiff 11.9% of the time and 5.6% of his changes put in play have been barreled. The higher average is at least partially due to getting more groundballs from the change, with a 47.2% GB rate compared to 38.8% last season. He’s throwing it more than he did last year, getting more swing and misses and more groundballs. Maybe this is a small sample thing, maybe he should be getting better results from his change.
Anyway, I wanted to highlight that Liberatore has looked like a significantly better pitcher as of late and if he can merely limit his bad innings to a run or two instead of 4 or 5, then we may be getting the Liberatore we wanted when this season started.