The Padres optioned Song to Triple-A El Paso on Monday.
The move corresponds with the Padres selecting Dustin Harris' contract from El Paso. Song has been with the big club since early May as a utility infielder and has a .202/.305/.263 slash line with 12 steals (in 16 attempts), one home run and 15 RBI over 134 plate appearances. He should operate as an everyday starter in Triple-A and could return to the majors should the Padres require infield depth.