The White Sox activated Pereira (pectoral) from the 10-day injured list Thursday.
Pereira has been shelved since late April with a right pectoral strain but has been cleared to return after going 5-for-14 with a pair of home runs in four rehab games with Triple-A Charlotte. The right-handed-swinging Pereira should play a decent amount in the Chicago outfield, especially versus left-handed pitching.