Peralta suffered a ligament strain in his left thumb during Sunday's game against the Miami Marlins. He underwent surgery on the same thumb prior to the season and missed the first 57 games.
Peralta, 34, was batting just .221 with five homers in 30 games while dealing with persistent thumb issues.
St. Louis also designated catcher Michael McKenry for assignment and recalled outfielder Jeremy Hazelbaker and right-hander Miguel Socolovich from Triple-A Memphis.
Hazelbaker, 28, is batting .250 with seven homers in 61 games for St. Louis this season. He was optioned to Memphis in mid-June.
Socolovich, who turns 30 on Sunday, is 2-5 with a 2.79 ERA in 35 appearances for Memphis. He had a 1.82 ERA in 28 games for the Cardinals last season.
McKenry, 31, played in just three games since joining St. Louis on July 7.