Cardinals acquire minor league pitcher Riley O'Brien in deal with Mariners to open offseason

In one of their first moves of the 2023 offseason, the Cards picked up Riley O'Brien, a right-handed minor league pitcher from the Mariners.

Although he has only a handful of MLB innings under his belt, O'Brien has been dominating the minor leagues recently. In a season that many Cards fans think will feature a changing of the guards, O'Brien could be a sensible low-key pickup for the Cardinals to add to their pitching depth.

"#stlcards have acquired RHP Riley O'Brien in a trade with the #Mariners. A PCL All-Star, the 28-year reliever had 86 strikeouts and a 2.29 ERA in 55 innings for Mariners' Class AAA team. He was set to become a minor-league free agent." - Derrick Goold

A native of Seattle himself, O'Brien was selected by the Tampa Bay Rays in the 8th round of the 2017 draft. In 2020, he was traded to the Reds, and began to pitch for the Triple-A Louisville Bats, pitching to a 7-7 record and 4.55 ERA to finish off 2020.

In 2021, Riley O'Brien was promoted to the Reds, making his MLB debut in September of that year. Following a trade to the Seattle Mariners in 2022, O'Brien pitched one inning for the big-league club before being sent down to Triple-A Tacoma. In 51 appearances out of the Tripla-A bullpen in 2023, O'Brien went 2-5, sporting a 3.11 ERA alongside 86 strikeouts in 56 innings.

"Riley O’Brien taking care of business with 2 inherited runners with 2 outs! #Mariners" - Kerri Hong

Sent to the St. Louis Cardinals in exchange for a player to be named later alongside cash considerations, O'Brien's new team represents a new chance for growth. With a bullpen ERA of 4.47 during the regular season, there is strong room for improvement among Cardinals relievers. With the right amount of luck and a few strong showings, perhaps 2024 could be Riley O'Brien's first full MLB season.

Riley O'Brien trade is one of the first of many

As exciting as the 2023 postseason and World Series were, the league has now entered a period of equally exciting transactions. With yesteryear's winners and losers attempting to correct mistakes during the season, expect to see a lot more hidden gems like O'Brien picked up.

Now with under 100 days left until the beginning of 2024 spring training, there will undoubtedly be a lot more shuffling of the league's rosters to come before then.