The Orioles traded Johnson to Philadelphia on Tuesday in exchange for Gregory Soto, Jeff Passan of ESPN.com reports.
Through 18 starts with Double-A Bowie, Johnson has recorded a 2.63 ERA and 1.32 WHIP through 65 innings this year. It's likely he heads to Double-A Reading to begin his tenure with the Phillies, though a promotion to Triple-A Lehigh Valley could come in the near future if the 25-year-old righty continues at his current pace.