Can Cardinals Closer Shed Struggles and Return to All-Star Form in 2027?

Growth, as St. Louis Cardinals’ manager Oliver Marmol pointed out repeatedly over the final month of the 2026 season, can be measured in a variety of ways.

One way, of course, is the standings – an area where the Cardinals fell back a win from 2025 (78-84) to 2026 (77-85), one that was somewhat expected with the widespread youth on the roster and the club selling off veteran pitchers JoJo Romero and Dustin May for prospects at the MLB Trade Deadline.

Instead, the Cardinals tried to evaluate areas of growth in non-traditional ways in a non-traditional season in St. Louis.

Growth was having a defined core group of players – Alec Burleson, Jordan Walker, JJ Wetherholt, Ivan Herrera, Masyn Winn, Michael McGreevy, Kyle Leahy and Riley O’Brien – take major steps in their games and evolve into building blocks.

Growth was seeing Leo Bernal, Joshua Baez, Quinn Mathews, Cooper Hjerpe and Nathan Church live up to the hype that followed them from the Minor Leagues and show signs they can be depended on going forward.

Growth was Andre Pallante and Gordon Graceffo shaking off the struggles of 2025 and showing the fortitude to change the trajectory of their careers.

“This is a really young group, but there’s been a lot of progress with so many of these guys,” Marmol said. “You can go up and down the lineup and you see growth from so many of our guys. Then, go to the rotation and what McGreevy, Pallante and Leahy did this season, and the bullpen as well. Our staff has really enjoyed pouring into that group. They are hungry for information and they want to be coaches, so that’s made it a lot of fun.”

However, as president of baseball operation Chaim Bloom reminds, the Cardinals still have major gulfs between them and MLB’s top teams. The National League champion Brewers, after all, finished 26 games ahead of St. Louis and battered the Cards in 11 of 13 head-to-head meetings. Much more growth is needed for the Cards to better navigate the difference the rebuilding and contending.

With growth being the focus, let’s look back at the performances by individual players in the 2026 season and how they will figure into the Cards’ plans going forward in 2027 and beyond:

Player name: Riley O’Brien

Age: 31

How acquired: Acquired by Cardinals on Nov. 5, 2023, in a trade with the Mariners for cash

2026 statistics: 66 games, 3-9, 4.08 ERA, 64 IP, 5 HR allowed, 64 strikeouts, 29 walks, .227 batting average allowed

Key numbers: In his first full MLB season, O’Brien finished 2026 tied with Padres’ superstar closer Mason Miller for the National League lead in saves with 38. O’Brien went 24 of 28 in save opportunities over the first half of the season to make his first MLB All-Star Game. However, he struggled over the final 2 ½ months by going 0-6 and just 14 of 18 in save opportunities.

Looking back to 2026: O’Brien’s season is a difficult one to measure because it was easily the best season of his career, but also one that finished with several struggles in high-leverage spots late in the season. He gave the Cardinals a tremendous boost early in the season when he took over the closer’s role and was one of baseball’s best early in the season. Locking down 24 of his first 28 save opportunities earned O’Brien a trip to the MLB All-Star Game, quite an accomplishment for a player who had never had much success with the Reds, Mariners or Cardinals previously. However, his struggles came in the second half when hitters started laying off his sweeper, essentially making O’Brien a two-pitch pitcher. His meltdown against the Phillies on August 23 – when the Cardinals led by four runs with two outs in the ninth and had a 99.6 percent win probability only to lose 6-4 on a walk-off homer by Kyle Schwarber – was easily the most crushing loss of the season for the squad.     

Looking forward to 2027: Did the Cardinals see enough good things from O’Brien in 2026 to stick with him as their closer? Or were his second-half struggles – he went 0-6 with four blown saves after the MLB All-Star Game – cause for the club to move on? O’Brien bravely admitted that his struggles late in the season got to him mentally and rattled his confidence. O’Brien’s ability to miss bats is impressive and he certainly has the pitch arsenal to be a steely closer in tough spots. But he does need another pitch to get hitters out when they aren’t chasing his sweeper. Having a closer under club control financially is very important for the Cardinals and they are likely to start 2027 with him as their closer again.

Denton’s analysis: It’s no coincidence that O’Brien’s struggles started about the time that veteran reliever JoJo Romero went out with an appendicitis and they only worsened when the crafty lefty was dealt to the Milwaukee Brewers. Mild-mannered and quiet, O’Brien needs a strong supporting cast around him to help him through tough times and to remind him of his enormous potential as a reliever. The Cardinals would be wise to pursue Romero again when he becomes a free agent after the World Series – because of what he can do against left-handed hitters and because of the calming influence he brings to a bullpen with his leadership qualities. That might be the best thing the Cardinals can do to help out O’Brien in the 2027 season.