3 Best Riley O'Brien Trade Fits for St. Louis Cardinals to Consider

The Cardinals should be looking to get the most out of their stars while they rebuild.

Apr 10, 2026; St. Louis, Missouri, USA; St. Louis Cardinals pitcher Riley O'Brien (61) throws in relief in the ninth inning against the Boston Red Sox at Busch Stadium. Mandatory Credit: Tim Vizer-Imagn Images | Tim Vizer-Imagn Images

The St. Louis Cardinals are in the middle of a very aggressive rebuild right now. They traded a trio of pitchers at the trade deadline last season despite being one of the better teams in the National Leageu Central. The front office seemingly understood that they weren't going to contend for a World Series, so a few moves like that became necessary.

The Cardinals continued their rebuild during the most recent offseason by trading a few of their top players.

This season, the Cardinals are winning again, but they could still look to trade some of their top players, like reliever Riley O'Brien, who's burst on the scene this year. O'Brien has been one of the better pitchers in the Cardinals bullpen, so he almost certainly has enough trade value to warrant a deal.

Which teams could target him if the Cardinals throw him on the trade block?

Los Angeles Dodgers

Mar 27, 2026; Los Angeles, California, USA; Los Angeles Dodgers pitcher Edwin Diaz (3) delivers to the plate as he earns a save in the ninth inning against the Arizona Diamondbacks at Dodger Stadium. Mandatory Credit: Jayne Kamin-Oncea-Imagn Images | Jayne Kamin-Oncea-Imagn Images

The Los Angeles Dodgers make a lot of sense as a trade fit. They recently lost Edwin Diaz to an elbow injury that required surgery. He's expected to be out for a few months. After surgery, it's always unclear how quickly a player will return to their prior form. Trading for a pitcher like O'Brien would make a lot of sense after the Diaz inury.

The Dodgers' bullpen also struggled mightily last season. They were dominant on their way to the World Series title, but the bullpen struggled. Without Diaz, it could begin struggling again. O'Brien has been a very consistent piece of the Cardinals bullpen, so a move to the Dodgers almost makes too much sense.

Toronto Blue Jays

Apr 20, 2026; Anaheim, California, USA; Toronto Blue Jays pitcher Jeff Hoffman (23) reacts after striking out Los Angeles Angels second baseman Adam Frazier (20) during the ninth inning at Angel Stadium. Mandatory Credit: William Liang-Imagn Images | William Liang-Imagn Images

The Toronto Blue Jays are banking on Jeff Hoffman eventually returning to form, but it doesn't seem like that's going to be the case. He struggled to the tune of a 4.37 ERA last season. This year, his ERA sits near 8.00.

The Blue Jays are struggling. They need another quality option in their bullpen if Hoffman is going to continue to struggle. Adding a pitcher like O'Brien with the team control that's left on his contract would be the perfect move.

Kansas City Royals

Apr 4, 2026; Kansas City, Missouri, USA; Kansas City Royals hat sits in the dugout during the sixth inning against the Milwaukee Brewers at Kauffman Stadium. Mandatory Credit: William Purnell-Imagn Images | William Purnell-Imagn Images

The Kansas City Royals came into the season with a star closer in Carlos Estévez. But Estévez struggled in spring training and early in the season. His velocity was way down, and he eventually landed on the injured list.

Trading for a controllable player like O'Brien makes the most sense. If Estévez continues to struggle, O'Brien could help close games. If the Royals closer returns to form, then O'Brien can work as a lights-out setup man. Either way, adding him to the bullpen is a big step in the right direction in Kansas City.