Treinen (shoulder) threw a successful 31-pitch bullpen session prior to Saturday's game against the Angels, Martin Gallegos of MLB.com reports.
The veteran closer reportedly came away healthy from the session, and he'll now get a rest day Sunday. Treinen is next slated to pitch a rehab outing with one of the organization's minor-league affiliates Monday, and if he remains free of setbacks, he's projected for activation when first eligible Wednesday.