Zambrano (6-4, 4.34 ERA) has been sidelined since July 1 because of lower back soreness.
Randy Wells (1-3, 6.80 ERA) will start Sunday and Rodrigo Lopez (1-2, 4.02 ERA) will go Monday when the Cubs face the Phillies. The Cubs needed to chose between Lopez and Ramon Ortiz for the fifth spot in the rotation. Ortiz, 38, was expected to go to the bullpen.
Andrew Cashner, who has been on the disabled list since April 6 with a strained right rotator cuff, was back in Mesa, Ariz., to continue his rehab. He will continue to build arm strength by throwing long toss before working toward throwing off a mound in a couple weeks.