Matt Koperniak News: Booted from 40-man

Published on December 17, 2025

The Cardinals designated Koperniak for assignment Wednesday, Jeff Jones of the Belleville News-Democrat reports.

Koperniak will lose his 40-man roster spot in order to make room for Dustin May, who officially signed with St. Louis on Wednesday. Koperniak, 27, spent all of 2025 at Triple-A Memphis and endured his worst minor-league season yet, slashing .249/.322/.387 across 537 plate appearances.