Velasquez will start Tuesday's home opener against the Mariners, Scott Merkin of MLB.com reports.
Velasquez joined the White Sox in mid-March and will begin the regular season as part of the starting rotation. He made 25 appearances (21 starts) between the Phillies and Padres last year and posted a 6.30 ERA and 1.48 WHIP in 94.1 innings.