Treinen (elbow) kicked off a minor-league rehab assignment with Single-A Ontario on Saturday, MLB.com reports. He tossed a scoreless and hitless inning while striking out two batters.
Treinen's appearance with the Single-A club was his first game action since he tossed a clean frame for the Dodgers against Baltimore on June 19. The veteran reliever landed on the injured list shortly thereafter due to a right elbow inflammation, and while he's been throwing since early July, he's taken a slow road back to the big-league squad. Trienen may need several more rehab outings before he's cleared to return, but he could be activated from the IL in late August or early September.