Estrada (elbow) kicked off a minor-league rehab assignment with Single-A Lake Elsinore on Friday, per MLB.com.
Estrada landed on the injured list April 10 due to tightness in his right elbow. The righty reliever resumed playing catch shortly thereafter and is now pitching in games again. Estrada tossed a clean inning with one strikeout in his first rehab appearance Friday and may not need a lengthy stint in the minors before he's brought back up to the big-league bullpen.