What Pitchers are “Shaping” The 2026 St. Louis Cardinals Bullpen?

The St. Louis Cardinals’ season is in full swing, and we’re starting to get to more meaningful early sample sizes when it comes to performance and consistent data on pitch shapes. While it’s true that some of the overall numbers aren’t all that impressive. Some of the Cardinals’ relievers are throwing some really exciting stuff, and I think there are reasons for SOME optimism with the current group, and I will highlight the pitchers who are really doing some fun things from a shape standpoint.

Entering Sunday’s contest, the Cardinals’ bullpen had the 21st-best FIP in the league at 4.72 according to Fangraphs. The 4.89 xFIP puts that group in 29th, ahead of only the Washington Nationals at 4.89. They’re K% of 16.9% also ranks 30th in baseball. Again, the performance numbers as a group will tell you this group has been nothing short of a disaster, and the eye test watching the first 2 plus weeks of the season, you would agree that there has been a LOT of contact and balls in play against this group. However, when you look at a different stat that can more or less tell you about what effect a bullpen has on games, WPA (Win Probability Added), the Cardinals’ bullpen ranks 7th in MLB at 0.76

I want to highlight some relievers who are doing some really exciting things from a pitch shape standpoint that should give fans more optimism that the bullpen in 2026 might not be AS bad as what we’ve seen so far.

Let’s start with Riley O’Brien. I would challenge any fan to call Riley anything except a strength at the back end of games for the Cardinals so far in 2026. He has not allowed a run in his first 8 innings of the season, and he has a minuscule WHIP of 0.48, and 3-3 in Save opportunities.

Jumping over to Baseball Savant, O’Brien has used his turbo sinker 61% of the time and is averaging 97.5 MPH and getting 6.8 Ft of extension, which is above average, making the perceived velocity 99-100 MPH with 17.1 inches of arm side run. This has to be nearly one of the most unfathomably hard pitches to hit in baseball. He also has an xwOBA of just .190 against opposing batters – It’s dominant.

Pair that pitch with his sweeper, that’s generating 17.6 inches of GLOVE SIDE run the opposite direction of his sinker and generating over 2400 RPM of spin, and has a whiff% of 41.7%. Almost half of the sweepers he throws generate a swing and miss, and all 3 at bats that have finished with a sweeper have resulted in a strikeout.

Former MLB pitcher Josh Beckett used to talk about making X’s with his pitches in the strike zone to keep hitters off balance, and when O’Brien has two distinct pitches that move a foot and a half in the OPPOSITE direction, one would think that would predict future success.

JoJo Romero is riding his big slider, and the early results have been really fun!

17.5 inches of glove side run is an absurd number from his slider that also produces almost 2800 RPM’s. The pitch has had some hard contact against it but he has managed to get outs when he needs it most and chances are its front dooring it to lefties, like he did to Roman Anthony Friday night and Anthony all but gave up on a ball that looked like it was thrown straight at his right hip and landed on the inner 1/3 of the zone.

Romero’s sinker has been the “out pitch” so far this season. Most teams are hunting that big slider and for good reason. JoJo throws it well, and if you’re not ready for it, you won’t hit it. To counter that, Romero has been jamming and sawing off batters with his sinker that has a .147 wOBA and an average LA of -5. Killing worms and making firewood for the winter!

How about the other lefty in the pen, Justin Bruihl? I did a deep dive back in the winter when the Cardinals acquired Bruihl and said there is more to this guy than meets the eye, and I think fans are starting to see that.

Bruihl’s sinker has been a strong offering for the Cardinal lefty so far. Generating over 17 inches of arm side run and an average LA of -3 degrees (insert that thing about worms and firewood from before)

NEW TO THE PARTY in 2026, Bruihl is throwing a changeup and has ditched his cutter. He has thrown the pitch exclusively to RHH, and it’s yielded a wOBA of just .217. Given that Bruihl has a FIP of 5.83 in his career against RHH and now has a weapon to potentially neutralize opposite-handed batters, he could see a significant uptick in production in the bullpen in 2026. Oh, and it’s killing spin and generating only 1425 RPM’s.

At the time, when the Cardinals acquired George Soriano, most Cardinals fans were a bit puzzled by the move and, understandably so. That was one of the “trust me, bro” moments for Chaim Bloom and his front office, whose internal model was telling them that, despite the 8+ ERA in 2025, there was still a lot to like about Soriano.

Let’s start with the slider. The action he gets with the pitch reminds me of Giovanny Gallegos, where it doesn’t sweep across the plate, but the bottom drops out from underneath it, and at nearly 2700 RPMs, that’s really encouraging, the pitch has been a little erratic as you can see the plot is a little scattered but that is something, as his bread and butter, I expect he will iron out through the season.

Soriano’s changeup is also really fun. At 90 MPH its almost like a Splitter instead of a changeup. With an xwOBA of .141 and 1531 RPM’s, it gets that really good spin killing/tumbling action on the pitch. Not quite Bugs Bunny but it certainly falls off the table at an impressive rate, and playing off of a 97 MPH fastball, it causes just enough separation to get LHH off stride and pop it up or swing over the top of it entirely. Coming back full circle to Andre Granillo, that is something that he did not possess the ability to do against opposite-handed hitters; the Cardinals took the chance on the pitcher with less flexibility but a higher upside.

The last reliever I will highlight is Gordon Graceffo. The Fastball, while firm, is slightly below average in terms of movement and profile. The fact that he throws it 40% of the time is a little bit interesting to me. Perhaps the 47-degree arm angle is doing some of the work on the deception with that. What truly sets Graceffo apart is his 12-6 curveball:

Big hammer. Just needs to “nail” the location. I’ll see myself out…

a wOBA of .142 and a spin rate of 2758 RPM’s. I’d like to see him lean on the curveball, maybe just a little bit more (hopefully not at the expense of his UCL). I don’t really think I need to say much more beyond it’s a big, beautiful breaking ball.

Side note: not an elite pitch, but Graceffo’s changeup has a little more upside to it as well, maybe if he became a guy who pitched backwards and stole strikes or generated early swings and misses with his secondary stuff and then blew guys away with 95 at the top of the zone with his release height that could be an avenue to a next level in his game. Just spitballing what I see and how to maximize what he does best.

This probably isn’t going to be the 2024 Cardinals bullpen that nearly led a mediocre team to a wild-card berth. But, it does feature some interesting names that COULD elevate the ceiling of this team if they unlock the correct sequences and mix of pitches. I think there is more in the pen than most thought, but both things can still be true: the Cardinals’ bullpen might be better than we think, and it’s not good enough to meaningfully change the outcome of the season as currently constructed.

-Thanks for reading

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