Manager Dave Roberts said Tuesday that Treinen (elbow) will be activated from the injured list "very soon," Jack Harris of the California Post reports.
Treinen was cleared to begin a rehab assignment Aug. 15 and has since fired 6.1 shutout innings while striking out eight batters and walking two between Single-A and Triple-A. The 38-year-old reliever has posted a 3.52 ERA and 1.35 WHIP across 23 innings in the majors this season and will likely work in middle relief once activated.