The Cardinals selected Pallante's contract Monday and added him to the Opening Day roster.
The 23-year-old produced 3.2 scoreless innings on the mound this spring, allowing just one hit and one walk while striking out four over three appearances. Though he made 22 starts between Triple-A Memphis and Double-A Springfield in 2021, Pallante is expected to serve as a multi-inning arm out of the bullpen for St. Louis.