Zambrano, who will start the season opener on March 31 against the Milwaukee Brewers, gave up two hits and three walks over six scoreless innings against Oakland's Triple-A team in Phoenix.
Meanwhile, Wood, one of the candidates for the closer's job, did not throw on Friday, but is expected to pitch in consecutive games Sunday and Monday. The Cubs didn't want Wood riding a bus for the long trip to Tucson after missing a game on Wednesday because of back spasms.
Cubs manager Lou Piniella says he will make an announcement on Monday to name the closer and how the team will fill the two rotation spots between Jason Marquis, Jon Lieber and Ryan Dempster.
If there is one matter still to be resolved this spring that has Piniella concerned it's who else can play center field.
"The only concern I really have here is what do we do in center field," said Piniella, who has tabbed Felix Pie as the regular there. "We only have one. We've tried Ronny [Cedeno] out there, but since we've kept him in the infield, it's done good for him."
The Cubs don't plan on carrying both Pie and Sam Fuld, who came into camp battling for the starting center-field job.
"I don't think we'll carry both young kids," Piniella said. "I don't think I can play [Daryle] Ward or [Matt] Murton out there."
Ward and Murton would probably agree.
As far as the other decisions, the personnel is in camp. Marshall made a good impression in his start against the Colorado Rockies on Friday. He gave up two runs on five hits and two walks over four innings. He seems to be the odd man out in the Cubs' plans -- there's no room in the rotation or the 'pen for him.
"I'm just looking to put together a nice spring to get to where I want to be at the beginning of the season," Marshall said. "I know the numbers are what they are, and it's tough in my circumstance. Hopefully, I've been pitching well enough that if they need me in the bullpen or to fill in for the starting rotation, I'll be there for them. I love Wrigley Field and I love pitching for the Cubs."
The left-hander's curveball was working well and he struck out three, including sluggers Matt Holliday and Todd Helton.
"I felt I continued to get stronger the higher the pitch count got and that's a good thing for me," he said. "I threw some good curveballs today, and some not-so-good curveballs."
"It was a very respectable performance," Piniella said of Marshall. "I've been pleased with his work. He's ready to go, and he's there for us now in a backup role, starting-wise, if necessary."
Marshall's name has been mentioned in trade rumors. The Baltimore Orioles were one of the teams who had scouts in the stands on Friday.
"I don't pay any attention to those guys," Marshall said. "They're there every day."
"We like Marshall," Piniella said. "He competes, and he looks bigger and stronger than last year. We just have to keep him pitching."
And for those of you in Tucson who were wondering why Piniella was wearing No. 86, it's because he forgot his jersey in Mesa, Ariz. It happens.
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.