Cardinals' Riley O'Brien Won't Join Korea in WBC After All

Riley O'Brien will not pitch in the WBC.

Sep 20, 2025; St. Louis, Missouri, USA; St. Louis Cardinals relief pitcher Riley O'Brien (55) pitches against the Milwaukee Brewers during the eighth inning at Busch Stadium. Mandatory Credit: Jeff Curry-Imagn Images | Jeff Curry-Imagn Images

The St. Louis Cardinals had 17 players competing in the World Baseball Classic back in 2023. This year, that number is much smaller, and it shrunk after the Cardinals traded away some of their veteran players.

Slugger Ivan Herrera was denied insurance coverage for the tournament, so he had to withdraw from Team Panama, and reliever Riley O'Brien was delayed in joining Team Korea after suffering a calf injury in spring training.

Reports surfaced on X that O'Brien still isn't quite in the best physical condition to pitch in the WBC. Jeff Jones of the Belleville News Democrat confirmed this and reported that O'Brien is officially out for the rest of the tournament.

Riley O'Brien out for WBC

Sep 11, 2023; Baltimore, Maryland, USA; A detailed view of the 9/11 ribbon on a St. Louis Cardinals hat in the dugout before the game against the Baltimore Orioles at Oriole Park at Camden Yards. Mandatory Credit: Tommy Gilligan-Imagn Images | Tommy Gilligan-Imagn Images

O'Brien was one of the Cardinals' top relievers last season after they sold at the trade deadline. He went 3-1 with a 2.06 ERA in 42 appearances and recorded six saves.

There aren't quite as many Cardinals present in the WBC this year, so with O'Brien now out for the rest of the tournament, that number continues to shrink. Ultimately though, it might be for the best at this point that O'Brien does not pitch in the WBC.

The calf injury slowed him down a little bit, and while he has since returned to action, the priority now should be for him to get ready for the 2026 season. The best course of action is to remain with the Cardinals rather than to risk further injuries by ramping up too quickly just to get back into action for the WBC.

O'Brien could compete for opportunities to be the club's closer this season along with relievers Matt Svanson and Ryne Stanek. He is a high-velocity pitcher that can be slotted in at the back of the bullpen and towards the end of games.

If he can stay off the injured list, the Cardinals' bullpen should be just fine in 2026. There is a lot of depth there.

Unfortunately though, it appears as though his chances of pitching in the WBC have come and gone. But if he remains healthy at spring camp, then he should be a solid option for the bullpen late in games and could even potentially become the team's full-time closer.

It will be interesting to see if he can stay healthy and be ready in time for the start of the season, but his chances of pitching in the tournament appear to be gone.