Hays (calf) will begin a rehab assignment with Triple-A Charlotte on Friday, LaMond Pope of the Chicago Tribune reports.
Hays has been shelved since May 4 due to a left calf strain and was moved to the 60-day injured list in early June after suffering a setback in his rehab assignment. He's made enough progress over the last month to resume playing minor-league games, but given his lengthy stint on the shelf, Hays could require an extended stay at Charlotte before rejoining the White Sox's active roster.