This is a bad time for the Cardinals to have their closer going sideways. It is the wrong time for the Cards to have their closer flattened out. It is the wrong time to be playing a division-heavy schedule without their closer’s heavy sinker.
What’s up with Riley O’Brien?
Well, his sinker is up.
Which isn’t the preference or the plan. The Cardinals and O’Brien want the sinker to well, you know … sink.
From what we can tell, O’Brien’s sweeper is still a highly effective pairing to go with his sinker. But the sinker isn’t cooperating.
Though the Cardinals outlasted the persistent Pirates Tuesday for a 9-6 win in 10 innings, O’Brien couldn’t preserve a two-run lead in the ninth and was knocked about for his fourth blown save of the season.
In his last 10 relief appearances O’Brien has been assaulted for a 7.45 ERA, .350 batting average, .447 on-base rate and a .425 slugging percentage. His strikeout-walk ratio is out of whack. His ground-ball rate is way down.
This is all a stark contrast from O’Brien’s brilliant, virtually perfect, opening phase of the season. Over his first 13 appearances this spotless, blameless right-hander didn’t concede a single run or walk a hitter.
In those first 13 walk-ons, opponents had five hits in 33 at-bats against O’Brien’s sinker. No harm.
In his last 10 entries into the closer’s pressure-sphere, opponents have slashed and smashed O’Brien’s sinker for 12 hits in 25 at-bats in a barrage that included a double and homer. That’s a .480 average and .600 slugging percentage.
— The Before: first 13 relief gigs: 45 batters, six hits, no walks, one hit batsman, 15 strikeouts, no runs.
— The After: 10 reliever assignments: 47 batters, 14 hits, three walks, four hit batsmen, 10 strikeouts, eight earned runs.
I went searching for data that could make sense of the symptoms and explain a performance turned haywire. I wanted to see what had changed.
Oh, boy.
Let’s survey the “before” and “after” categories. Lots of information in here. You can see the signs of … something that validates our concern level. O’Brien hasn’t been the same.
All stats are based on O’Brien’s sinker.
Whiff-swing rate: 28.8% … 13.8%. One of the most troubling indicators of them all. My goodness that’s a loss of 15 percent.
Strikeout rate: 32.6% … 20.8%. This means more balls in play. And, more importantly, fewer wipeout pitches to put an end to a threat.
Walk + HBP rate: 2.2% … 15.5%. No elaboration necessary. The command has been erratic.
Ground-ball rate: 69% … 48.3%. For a sinkerball specialist, that’s an eye-opening reduction.
Avg. exit velo: 83 mph … 91.6 mph. That’s a significant jump for opposing hitters. Their bat speed is producing some rockets on contact.
Hard-hit rate against: 29.2% … 47.8% Hitters are punishing the sinker now. That wasn’t the case earlier.
Vertical drop: 26 inches … 21 inches. Yeah, the sinker has a lot less sink. Which is what we suspected. This is a big deal. I’ll explain more later.
Heart of plate: 21% … 34%. He’s landing pitches right in the middle of the strike zone. That’s not helpful.
Release height: 5.75 inches … 5.55 inches. The arm slot has changed. The batting average on balls in play against O’Brien in his first 10 assignments was .180. In his last 13 appearances, the BABIP is .450. Perhaps there’s been a dash of bad luck. But that doesn’t explain the problem.
What a pitching coach (who shall remain anonymous) told me:
1. When a sinker loses vertical depth, it flattens out and enters the so-called dead zone. Meaning that it stays on the exact same plane as a typical big-league hitter's bat path. This explains why O’Brien’s whiff rate has drastically declined – and why the hard-hit rate against him has doubled.
2. O'Brien's release point has dropped by about two inches during this damaging stretch. When a pitcher drops his arm slot slightly – which can be a sign of fatigue, or a mechanical glitch – it alters the spin axis of the pitch. So instead of having that heavy, downward effect, the spin becomes more horizontal. And much easier to elevate. Which leads to fewer ground balls.
3. In the "Before" phase, O'Brien’s sinker made regular visits to the “shadow” zone … the edge of the strike zone. In his recent phase, his sinker is finding the heart of the plate. And at that point the flat sinker is batting practice.
4. In his first 13 appearances, the batting average on balls in play against O’Brien’s sinker was .205. In his last 10 assignments, that BIP average is near .500. Bad luck? Not so much. The erosion of his whiff-swing and strikeout rates tells us the hitters are getting to his sinker much easier now, and they’re making O’Brien pay.
5. The exit-velocity increase is hazardous, and that’s shown by the .480 batting average against the sinker in O’Brien’s current rut. A 98 mph pitch loses its movement and stays over the plate. And that makes a hitter’s eyes get bigger.
6. Finally the pitching coach told me this: “O’Brien isn’t ‘finishing’ on the sinker. Is it fatigue? Is he hurting a little? Relievers go through these cycles. This could be something minor … but it could also develop into something major. What’s the old saying? ‘The truth shall be revealed.’ That sums it up.”
HOW DID THIS HAPPEN?
We don’t know for sure, and the Cardinals aren’t about to share any private or proprietary information. (Nor should they.)
But O’Brien’s crash began on April 25 with that memorable – and alarming – 39-pitch marathon that covered parts of two innings (8th and 9th) in a blown-save, 11-9 loss to Seattle. He faced nine hitters while getting smacked around for four hits and two earned runs. To that point of the season, O’Brien hadn’t thrown more than 19 pitches in an appearance.
On May 2, O’Brien threw 26 pitches (yielding two runs) for a difficult close-out for a save in a 3-2 cliffhanger win against the Dodgers. On May 10, O'Brien reached for 31 pitches during the blown-save loss at San Diego in the fourth and final game of the series. And then Tuesday (May 19), the price for the squandered ninth-inning save was 22 pitches.
Has manager Oli Marmol pushed O’Brien too hard? Has this been too much for a reliever that has a history of injuries? It’s a legitimate question. O’Brien may be healthy, but the proverbial “dead arm” malady is common with pitchers.
But before casting blame on Marmol, we should remember O’Brien’s work schedule in 2025. He answered 14 relief calls that lasted more than an inning including six that covered two innings. Last season O’Brien had 10 different shifts in which he threw anywhere from 25 to 39 pitches.
The point is, O’Brien proved to be a durable reliever last season, capable of handling more strenuous assignments. So Marmol had no reason to assume O’Brien would be more likely to struggle physically in 2026. But an adjustment is in order.
As I mentioned at the beginning of The Review, the Cardinals will be spinning in a crucial carousel of a schedule. They have two more games against the Pirates, travel to Cincinnati for three, move over to Milwaukee for three, then return home for three matchups against the Cubs.
The Cardinals may have to take more of a committee approach during this busy time, which could mean an opportunity to close for George Soriano, Ryne Stanek, JoJo Romero, Gordon Graceffo and Matt Svanson.
Stanek has really improved, having a streak of seven consecutive scoreless appearances and posting a 0.90 WHIP. He has seven strikeouts and walked three in 6 and ⅔ innings.
Be careful, Cardinals. A burned-out O’Brien wouldn’t be as valuable to his team in protecting late leads. And a lesser version of O’Brien wouldn’t have as much trade value for an opportunistic president of baseball ops Chaim Bloom.
Thanks for reading …
–Bernie
Bernie was inducted into the Missouri Sports Hall of Fame in 2023. During a St. Louis sports-media career that goes back to 1985, he’s won multiple national awards for column writing and sports-talk hosting – and was the lead sports columnist at the Post-Dispatch from 1989 through 2015. Before that Bernie spent a year at the Dallas Morning News, covering the Dallas Cowboys during Tom Landry’s final season (1988) plus the sale of the team to Jerry Jones and the hiring of Jimmy Johnson as coach. Bernie has covered several Baseball Hall of Fame managers during his media career including Tony La Russa, Whitey Herzog, Earl Weaver, Joe Torre and (as an interim) Red Schoendienst. In his career as a beatwriter and columnist, Bernie covered Pro Football Hall of Fame coaches Joe Gibbs, Tom Landry, Jimmy Johnson and Dick Vermeil on a daily basis.
Bernie has covered and written about many great St. Louis sports team athletes including Albert Pujols, Kurt Warner, Brett Hull, Yadier Molina, Adam Wainwright, Jim Edmonds, Marshall Faulk, Scott Rolen, Mark McGwire, Orlando Pace, Isaac Bruce, Torry Holt, Adam Wainwright, Chris Carpenter, Al MacInnis, Brian Sutter, Bernie Federko, Chris Pronger, Dan Dierdorf, Jackie Smith and Aeneas Williams. Bernie covered every baseball Cardinals’ postseason game from 1996 through 2014 and was there to chronicle teams that won four NL pennants and two World Series. He provided extensive coverage on the “Greatest Show” St. Louis Rams and has written extensively on the St. Louis Blues, Saint Louis U, and Mizzou football and basketball. Bernie was/is a longtime voter for the Baseball Hall of Fame, Pro Football Hall of Fame, Heisman Trophy and the St. Louis Cardinals Hall of Fame.
You can access his columns, videos and the podcast version of the videos here on STL Sports Central, catch him regularly on KMOX (AM or FM) as part of the Gashouse Gang, Sports Rush Hour, Sports Open Line or Sports On a Sunday Morning shows. And you can catch weekly “reunion” segments here at STL Sports Central featuring Bernie and his longtime friend Randy Karraker.