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Cardinals Acquire Riley O’Brien From Mariners

By Nick Deeds | November 6, 2023 at 11:38am CDT

The Cardinals and Mariners got together on a minor trade yesterday, with St. Louis acquiring right-hander Riley O’Brien from the Mariners, according to MLB.com’s transactions log. The return headed to Seattle in exchange for O’Brien is not currently known, but figures to be insignificant. O’Brien is slated to hit minor league free agency if not added to the 40-man roster. While the Cardinals have not announced that O’Brien’s contract will be selected, they have just 38 players on their 40-man meaning no corresponding move would be necessary to do so.

O’Brien, 28, was an eighth-round pick in the 2017 draft by Tampa Bay. He pitched well in three seasons with the organization while seeing time as both a starter and reliever. By the 2019 season, he had reached Double-A with a 3.93 ERA and 24.2% strikeout rate in 68 2/3 innings of work at the level. Though O’Brien did not pitch in the 2020 campaign thanks to the cancelled minor league season, he was swapped to the Reds in a deadline deal that brought Cody Reed to the Rays that summer.

O’Brien spent almost the entire 2021 season at the Reds’ Triple-A affiliate in Louisville, where he struggled somewhat to a 4.55 ERA across 23 appearances (22 starts). Despite that uninspiring performance, O’Brien was called up to make his big league debut near the end of September. Unfortunately, his sole appearance in the big leagues during the 2021 season did not go well as he walked three and allowed two home runs in just 1 1/3 innings of work. Cincinnati retained O’Brien on their 40-man roster throughout the 2021-22 offseason but ultimately designated the then-27-year-old righty for assignment in April in order to make room for left-hander Nick Lodolo on the 40-man roster.

That led the Reds to ship O’Brien to Seattle, where the Mariners had an open 40-man roster spot to offer the righty. While he returned to the big leagues in May and pitched a scoreless inning out of the bullpen, O’Brien’s 2022 season left plenty to be desired overall as he struggled to convert to full-time relief, posting a 7.03 ERA in 39 2/3 innings of work at the Triple-A level after being outrighted off the club’s 40-man roster in June.

Difficult as the 2022 season was, O’Brien returned to the Mariners in 2023 and pitched far better than he had the year before. Though he did not manager to make his way back onto the 40-man roster, O’Brien dominated the hitter-friendly PCL to the tune of a 2.29 ERA in 55 innings of work this year while striking out a whopping 37.7% of batters faced. Given those fantastic numbers at the Triple-A level this year, it’s easy to see why the Cardinals, who are known to be looking for bullpen upgrades this offseason, would be interested in taking a chance on O’Brien and finding out if his strong 2023 season in the minors could carry over to the big leagues in 2024.

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Seattle Mariners St. Louis Cardinals Transactions Riley O'Brien

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View Comments (13)
Post a Comment

13 Comments

  1. SweetBabyRayKingsThickThighs

    2 years ago

    Does this O’Brien also have rave reviews?

    2
    Reply
  2. CrayZ1

    2 years ago

    Who did they trade for him

    Reply
    • DarkSide830

      2 years ago

      prolly cash

      Reply
  3. rhendricks

    2 years ago

    FYI – Small typo in the last paragraph: “Though he did not *manage*…”

    Love the detailed write-up even for a depth move.

    Reply
  4. CardsFan57

    2 years ago

    Why would St. Louis use a 40 man roster position for this?

    1
    Reply
    • gbs42

      2 years ago

      37.7% K rate

      Reply
      • bob9988 2

        2 years ago

        Check out that walk rate. Over 5 per 9.

        Reply
        • gbs42

          2 years ago

          5.1 BB/9 certainly is concerning, though I’ve read the automated ball-strike system played some havoc with those numbers.

          Reply
  5. Shady mapleworth

    2 years ago

    Tyler O. hopefully is going to the mariners

    1
    Reply
  6. CardsFan57

    2 years ago

    All the big talk will return taking a bunch of fliers on mediocre pitchers.

    Reply
  7. eznod

    2 years ago

    THIS is the pitcher we’ve been waiting for from the Mariners…lol

    1
    Reply
  8. Gary R

    2 years ago

    Are you kidding me?

    Reply
  9. Farian

    2 years ago

    “Difficult as the 2022 season was” is not proper English. It has to be “AS difficult as the 2022 season was.” “As” isn’t optional. Grammar isn’t optional, Mr. Deeds.

    1
    Reply

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