Koperniak grew up in Adams, Massachusetts and attended Hoosac Valley High School, where he played baseball, basketball, and football.
After graduating from Trinity in 2020 with a Bachelor of Science degree in Biology, he initially intended to transfer to Kansas State University for his final season of collegiate eligibility.
[8] He slashed .322 /.443 /.470 in 58 games with Palm Beach before being promoted to Peoria Chiefs of High-A Central at the beginning of August.
Koperniak had six hits in 14 at-bats over four games for the Chiefs and was promoted a second time to the Double-A Springfield Cardinals.
[12] Koperniak split time between Springfield and Memphis again in 2023, slashing .287/.362/.427 with 18 home runs, 85 RBI, and 11 stolen bases over 129 games.