Zambrano had his first game action since June 25 when he pitched one inning for the Cubs' Rookie League team in Mesa, Ariz., Monday night. He faced three batters and struck out one.
He is to join the Iowa team in Des Moines on Wednesday and make his first appearance Thursday. Zambrano is not expected to join the Cubs until the end of the next road trip in Colorado, July 30-Aug. 1.
Zambrano began working out at the Mesa complex last week. His last game action was one inning June 25 at U.S. Cellular Field against the White Sox. He threw a tantrum in the dugout after the inning, accusing his teammates of not playing behind him and was suspended for three days. He was then placed on the restricted list.
When he does return, Zambrano, who was the Cubs' Opening Day starter, will be assigned to the bullpen.
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.