The Cardinals claimed Pereira off waivers from the White Sox on Thursday.
He's out of minor-league options, so Pereira will report directly to the big club. Pereira has slashed .225/.284/.438 with four home runs and a 5:30 BB:K across 88 plate appearances in the big leagues this season. The 25-year-old is sporting a .790 OPS against left-handed pitching and could slot into a short-side platoon role in center field with Nathan Church.