Riley O'Brien Could Be Key to Cardinals Bullpen Turnaround

The Cardinals' bullpen has struggled to start 2026.

Feb 14, 2026; Jupiter, FL, USA; St. Louis Cardinals pitcher Riley O'Brien (61) delivers a pitch during a spring training workout at Roger Dean Chevrolet Stadium. Mandatory Credit: Sam Navarro-Imagn Images | Sam Navarro-Imagn Images

The St. Louis Cardinals won three of their first five games to start the 2026 season. The starting rotation has performed well, and so has the offense. Unfortunately, the same cannot be said for the bullpen.

The bullpen surrendered 16 runs in the first three games against the Tampa Bay Rays, even losing a 4-0 lead in the second game of the series.

The Cardinals don't have the same weapons that they did last season. Ryan Helsley, Steven Matz and Phil Maton are all gone after the Cardinals sold at last year's trade deadline. However, Riley O'Brien has performed well since returning from an injury that cost him two weeks of spring training.

Former Cardinals writer John Denton believes that he will be the X-Factor once he is in full swing.

Riley O'Brien may be key to Cards' bullpen success

Mar 26, 2026; St. Louis, Missouri, USA; St. Louis Cardinals pitcher Riley O'Brien (61) reacts as he walks off the field after striking out Tampa Bay Rays third baseman Junior Caminero (not pictured) during the seventh inning at Busch Stadium. Mandatory Credit: Jeff Curry-Imagn Images | Jeff Curry-Imagn Images

"I think eventually this bullpen will stabilize," Denton said. "We all need to take into consideration that Riley O'Brien missed two and a half weeks of spring training. The Cardinals are bringing him along slowly. I think eventually he'll be their closer. They don't want to overextend him right now, he has a history of forearm injuries, they want to keep him at one inning right now."

O'Brien has appeared in three games for the Cardinals this season and has yet to allow an earned run. He even earned the win on Opening Day against the Rays.

He served as the team's closer down the stretch last season and allowed the bullpen to remain a strength for St. Louis even after making their three trades. The right-hander went 3-1 with a 2.06 ERA in 42 appearances and recorded six saves after being named the team's closer.

Once he is at full strength, the Cardinals' bullpen should be as well. He has a high-upside arm and can touch 100 mph with his fastball. As long as he can stay healthy, he is a viable option to serve as the team's closer, and could be the main factor in a potential turnaround for the bullpen.

It is still early in the season, so fans shouldn't panic just yet about the bullpen's struggles. But O'Brien getting back to full strength should be a boon for the Cardinals as they continue their rebuild and see what they currently have with their young roster.

We'll see where things stand once O'Brien is back to full strength.