Howard had his contract selected ahead of his start in Game 2 of Sunday's doubleheader versus the Braves, Scott Lauber of The Philadelphia Inquirer reports.
The 24-year-old is now officially on the 40-man and 28-man rosters as he gets set to make his major-league debut in Sunday's nightcap. Howard is one of the top pitching prospects in baseball and posted a 2.35 ERA, 0.96 WHIP and 38:9 K:BB over 30.2 innings at Double-A Reading last season.