Howard will be called up to start one of the two games in Sunday's doubleheader, Matt Breen of The Philadelphia Inquirer reports.
The 24-year-old was the likely candidate to start Sunday's game, and the team has now told him that he'll get the nod. It's unclear which of the two seven-inning contests he'll start. Since Howard isn't on the 40-man roster yet, he should be officially added to the major-league club sometime after Saturday's contest. The highly-touted prospect turned heads during summer camp, but the team secured an extra year of service time by letting him develop at the alternate training site to begin the regular season. If all goes well in his MLB debut Sunday, he could become a regular fixture in the Phillies' rotation.