Miguel Olivo has appeared in 54 games for Seattle, batting just .151 with five home runs and 18 RBI.
In 43 games this season for the Padres, Miguel Ojeda batted just .137 with six RBI. He was hitting just .193 since being sent down to Triple-A Portland.
Natanael Mateo has appeared in 48 games this season with Double-A Mobile, going went 3-4 with a 3.08 ERA and one save. Mateo, a Southern League All-Star, had one stretch where he threw scoreless ball over 16 straight appearances.
The Padres had previously acquired David Ross from Pittsburgh, sending J.J. Furmaniak packing. Ross, who had been playing at Indianapolis, was hitting just .211 at the Triple-A level.