The St. Louis Cardinals' biggest weakness in 2026 was the bullpen. It's hard to deny that fact.

St. Louis finished the 2026 season with the 20th-ranked bullpen ERA in baseball at 4.40 and the club tied for the third-most blown saves in baseball in 2026 with 30. If the Cardinals fix the bullpen, they're going to be significantly more competitive in the National League wild-card race in 2027. The Cardinals finished the 2027 season 11 games out of the final wild-card spot. The Cardinals went 77-85, one game worse than the year before, when Nolan Arenado, Brendan Donovan, Sonny Gray and Willson Contreras were all still in St. Louis.

With an improved bullpen, the Cardinals are arguably at least a .500 team right now, even if they do nothing else. On Tuesday, the Cardinals took a quiet step in that direction by acquiring Eduardo Rivera from the Boston Red Sox.

The Cardinals didn't have to give up much at all. St. Louis traded young pitching prospect Juan Garcia to Boston to get Rivera. Garcia isn't anywhere near the majors right now. Rivera, on the other hand, is someone who could help St. Louis right away on Opening Day to kick off the 2027 season.

The Cardinals Made A Good Move

In 2026, he made his big league debut with Boston. He pitched in four games, including three starts, and had a 6.30 ERA in 10 innings pitched. That's too small of a sample size to really think about, though. His performance in Triple-A is why he could be a sneaky big addition. Rivera logged a 2.96 ERA in 24 appearances, including three starts, with Triple-A Worcester.

Rivera has great size at 6'7'' and a blistering fastball from the left side. He's just 23 years old. If the Cardinals can get him on track and get his momentum from the minors to carry over to the big leagues, we're talking about someone who can help St. Louis' bullpen from the left side for years to come. St. Louis has team control for a while. Rivera will enter the 2027 season with rookie status still.

The bullpen is the biggest weakness for the organization. Rivera may not be a household name yet, but the Cardinals already have added a hurler who could make a legit impact and it's still just early November. Chaim Bloom and the Cardinals got a move on early. At this moment, Cardinals fans may not know much about Rivera yet, but St. Louis already has landed a guy who can help solve the organization's biggest hole.