The Cardinals acquired JoJo Romero in a trade back in 2022
This trade didn't seem like much back in 2022, Edmundo Sosa was losing playing time for the Cardinals so he was sent to the Phillies for a left-handed pitcher who had an ERA a shade under 8 across 3 seasons in Philadelphia.
Romero was a 4th round pick of the Phillies back in 2016 and made his MLB debut in the COVID-shortened 2020 season. He was part of a bullpen for the Phillies that just may be the worst bullpen in the history of baseball, as the Phillies bullpen had a 7.06 ERA in 2020.
In 2022 Romero only pitched in 2 games for the Phillies at the time of the trade but the Cardinals kept him with the big club, as he appeared in 13 games in the final two months of the season, recording a 3.77 ERA in those games. He was limited to just 27 games in 2023 but pitched well, as he had a 3.68 ERA, he cut down on his walks and had a 10.3 K/9. But Romero's steady improvement has continued in 2024.
So far this season Romero has gotten career highs in games played ( 38), ERA ( 2.68), innings pitched ( 37), ERA+ ( 155), WHIP ( 0.95), and H/9 ( 6.6). He has pitched in high-leverage spots all season long and has been the most dependable left-handed arm out of the bullpen. Sosa has been a solid role player for the Phillies and was a contributor to their run to the World Series in 2022, but the Cardinals found a diamond in the rough with Romero, who has shined bright in St.Louis.