Velasquez will start Sunday's series finale against the Marlins, Meghan Montemurro of The Athletic reports.
The 28-year-old had yet to be confirmed as a member of the Phillies' starting rotation, but he'll take the mound in the final game of the opening series. Velasquez has been up and down over the past few seasons and posted a 4.91 ERA and 1.39 WHIP last season, but he's performed well in summer camp and may benefit from the change in the team's pitching coach this offseason.