Cubs scratch Zambrano from Friday turn
Left-hander Sean Marshall replaced Zambrano.
Zambrano, 7-4 with a 3.35 ERA, worked a season-low three innings in his last start against Florida on Aug. 1, leaving the game lower back stiffness. He gave up two runs and three hits with three walks and two strikeouts.
Before Friday's game, Cubs manager Lou Piniella said there were no concerns about Zambrano's back.
"He hasn't complained about anything," Piniella said. "He's been doing his exercises. He should be nice and strong for tonight's performance."
However, a team spokesman said Zambrano came off the field shortly before the game's scheduled start with a recurrence of lower back stiffness.
Copyright 2009 by The Associated Press