Oh was placed on the 10-day injured list Monday with a left abdominal strain, Thomas Harding of MLB.com reports.
This helps explain why Oh hasn't pitched since May 30. The severity of the injury is not yet clear, leaving the veteran reliever without a timetable for his return. Look for Scott Oberg, Carlos Estevez and Jake McGee to handle the majority of setup duties while Oh is on the shelf. Phillip Diehl was summoned from the minors in a corresponding move.