The jump from Triple-A to the Major Leagues may be the hardest it’s ever been, and that’s true for both position players and pitchers. Sure, those on the mound seem to have an advantage in this day and age, but many young arms get rude awakenings when they step on that big league mound. It often takes resilience, patience and tinkering along the way for young pitchers to find their footing, things the Cardinals are positioned to offer their arms right now.
Gordon Graceffo and Luis Gastelum are the latest examples of that.
Two relievers who have had rocky moments for the Cardinals this year both hit their stride recently, with tweaks to their games unlocking them as leverage arms down the stretch for St. Louis.
While Graceffo had solid numbers to begin his season, things were very concerning under the hood. Graceffo’s 3.14 ERA in his first 43 innings of work came with a 6.25 xERA and 4.90 FIP, highlighting concerns around the second-lowest strikeout rate among qualified relievers (11.7%) and fortunate batted-ball results (.192 BABIP).
Two pitches in Graceffo’s arsenal were failing him as the year went on -- his cutter and his curveball. The cutter was his second-most frequently used pitch, used primarily against right-handed hitters, but he was not able to consistently get hitters out with that offering. While the curveball had much better metrics, it rarely induced swing-and-miss.
On July 9, Graceffo ditched his curveball while significantly cutting down on his cutter usage, and he introduced something new -- a biting slider with more depth to it than his cutter had before. It quickly became a pitch Graceffo leaned on heavily, and during the month of August, he used it 39.8% of the time, more than any other pitch in his arsenal.
Since then, Graceffo owns a 2.49 ERA in 25 1/3 innings of work, striking out 25.5% of the batters he’s faced, resulting in a much more sustainable 2.71 xERA and 2.81 FIP. That slider is yielding impressive results, as opponents are whiffing 31.1% of the time he throws it. All of that work was on full display when Graceffo acted as the opener against the Orioles on Aug. 27 and retired all nine batters he faced while striking out four of them.
Gastelum’s struggles were more evident than Graceffo’s upon his Major League debut back in July, but the change he needed to make was far more subtle. In his first 12 outings, Gastelum allowed 12 earned runs on 16 hits and five home runs, striking out just 10 batters in the process. His changeup, the pitch that got him to the big leagues, had a .333 batting average and an .833 slugging percentage against it in July.
This rough stretch raised many eyebrows. If the changeup is supposed to be his bread-and-butter pitch, it seemed like he had a long way to go in order to pitch at the big league level. But manager Oliver Marmol said the Cardinals identified that Gastelum was tipping that pitch to opposing hitters.
Gastelum cleaned up the pitch tipping, and he’s been lights out ever since. Over his last 10 outings, Gastelum has a 1.54 ERA while striking out a whopping 51.2% of the batters he’s faced. And that changeup? He struck out 17 batters with it in August alone to the tune of a 56.9% whiff rate, the highest percentage of any pitch thrown more than 70 times that month. He’s allowed just one hit off it the entire month.
As the Cardinals head into September, there are plenty of opportunities to go around in their new-look bullpen. Gastelum and Graceffo are joined by other young arms, like rookies Cade Winquest and Brycen Mautz, who are looking to carve out roles as future pieces in the Cardinals’ relief core. St. Louis is facing an innings deficit in its rotation and has opened up high-leverage opportunities at the back end of ballgames, so these young arms are going to be called upon often to fill important roles down the stretch.
It may not always look pretty, but as Graceffo and Gastelum have shown over the last month, sometimes it requires taking some lumps on the mound in order to unlock the best a young arm has to offer.