A pre-diffuser of an inner diffuser case of a gas turbine engine may comprise an annular outer wall and an annular inner wall radially inside of the annular outer wall to define a passage for primary airflow therebetween. The pre-diffuser may further comprise at least one strut extending radially between the annular inner wall and the annular outer wall and at least one aperture formed in the strut that extends radially through the strut, the annular inner wall, and the annular outer wall. The pre-diffuser may further comprise at least one hollow cavity formed in the strut, and the hollow cavity may be separate from the aperture.