Johnson (hamstring/illness) will begin a rehab assignment at Single-A Rancho Cucamonga on Sunday, Rhett Bollinger of MLB.com reports.
A viral infection sent Johnson to the injured list April 6, and he later suffered a hamstring injury while making a start in extended spring training. The 23-year-old righty said Saturday that he's recovered from both issues and has been facing hitters at the Angels' complex in Arizona, per Jack Janes of TheSportingTribune.com, so his return date will depend on how quickly he can ramp up his workload.