Lewis, who is scheduled to make an extended spring start Saturday in Surprise, will join Triple A Round Rock next following that game if there are no issues.
Lewis, who is coming back from a torn right flexor tendon, will make his rehab debut May 9 for Round Rock in Las Vegas with the plan for him to throw three innings. He will remain with the Express and should make a four-inning start May 14 in Tucson.
Lewis can remain on the rehab assignment for up to 30 days.
Lewis made his extended spring debut Monday with a 17-pitch inning. He said his arm felt great following the outing.