The Cardinals announced that outfielder Matt Koperniak has been designated for assignment. That’s the corresponding 40-man move for right-hander Dustin May, whose signing is now official.
Koperniak, 28 in February, has been with the Cards since signing with them as an undrafted free agent in 2020. From 2021 to 2023, he produced pretty solid results as he climbed the minor league ladder. Across those three seasons, he stepped to the plate 1,399 times. His 10.1% walk rate and 16.1% strikeout rate were both solid figures. He produced a combined line of .293/.375/.441, which translated to a wRC of 112, indicating he was 12% better than league average at the plate.
He seemed to find a new gear in 2024, his first full season at Triple-A. He hit 20 homers and slashed .309/.370/.512 for a 128 wRC+. That may have been a bit fluky, as he got some help from a .351 batting average on balls in play, but the Cards seemed to believe in him. They added him to the 40-man roster in November of that year to keep Koperniak out of the Rule 5 draft.
He spent 2025 back at Triple-A on optional assignment and his results backed up. His home run tally dropped to 14, despite taking 23 extra plate appearances. His BABIP dropped to a more average-ish .283. He finished the season with a .246/.317/.382 line and 85 wRC+.
The Cards are rebuilding and will be giving playing time to younger players in 2026 but Koperniak wouldn’t have been at the front of the line after that performance. He’s instead been bumped off the roster and into DFA limbo. The Cards will now see if there’s any trade interest in him. If not, he’ll be put on waivers. He does still have a couple of options remaining and is considered a strong defensive outfielder, with experience at all three spots. If some club out there likes him, they could acquire him and keep in Triple-A as depth as they hope for a bounceback at the plate.
Photo courtesy of Sam Navarro, Imagn Images

He’ll probably pass through waivers and remain in Memphis,
Personally, I hope some team takes a flyer on him to clear more at-bats for AAA outfielders.
Nice year in 2024, but he really flamed out this year. Sucks for him.
I think he flamed out because he proved everything in triple AAA,and kept it going in spring training, and still was not given a shot at the mlb level.
If he was with any other organization, he would have been called up by now, but the Cardinals had (have) a huge amount of left handed hitting outfielder. If he batted from the right side, probably would have been called up already imo.
Sounds like the perfect future third baseman for the Angels!
Released because he thought the earth wasn’t the center of the universe?
I see you.
Actually my son (Fever Pitch Guy) is the center of the universe
12.5 was definitely a bigger number than I expected for May. But, oh well, no harm on a one year deal.
Future Cleveland OF. Go spend that money Cleveland. 🙂