Stammen (shoulder) will begin a rehab assignment Tuesday with Single-A Lake Elsinore.
Stammen has been on the injured list since early July with right shoulder inflammation, so he could need multiple rehab appearances in the minors before the Padres activate him. Prior to landing on the shelf, Stammen appeared in 27 games out of the San Diego bullpen, logging a 3.34 ERA, 1.18 WHIP and 27:5 K:BB across 32.1 innings.