LHP Cooper Hjerpe
Cooper Hjerpe is the most junior of these options. He was drafted in 2022 and has yet to pitch beyond High-A Peoria. However, there is a lot to like about the deceptive lefty; while his fastball won't blow batters away, he is able to tunnel it well with his breaking pitches. Hjerpe looks to start 2024 in AA as a starting pitcher.
"Hjerpe appears almost fearless with the way he goes right after hitters, and despite his unorthodox mechanics, he throws plenty of strikes that should keep him in a starting role."- MLB.com
In Peoria this past year, Cooper got off to a decent start. In 41 innings, Hjerpe had a 3.51 ERA, 1.24 WHIP, and batters had a .183 batting average against him. He struggled slightly with walks (25) but struck out batters at a strong clip (51 K's in 41 innings). He did have a minor elbow surgery in May, and that limited his innings total this past year. He made two final starts in September and didn't pitch beyond the first inning in either game. He requires some buildup to be a starter again.
It would be a long shot for Hjerpe to pitch in the majors this year, especially in the rotation. The only way I see him being a starting pitcher in St. Louis would be if the Cardinals experienced a plethora of injuries and underperformance. I could see him getting a taste of the majors out of the bullpen towards the end of the year or the playoffs, similar to Adam Wainwright of old or Andre Pallante from a few years ago. It is highly unlikely that Hjerpe will make the starting rotation in 2024.