Caridad has had control problems all year, and in mid-April, he went on the DL with a right forearm strain.
Cubs manager Lou Piniella has tried to build a smooth transition from the starting pitchers, who have performed well overall this year, to closer Carlos Marmol. The newly anointed eighth-inning man is lefty Sean Marshall. Piniella did not use Marshall on Wednesday because Marshall had worked three games in a row and four out of five. But Marshall had to warm up in the ninth inning anyway when Marmol ran into control problems.
John Grabow, who has struggled early, worked part of the seventh and into the eighth before turning the game over to Zambrano.
Rumors persist the Cubs will re-sign veteran right-hander Bob Howry, who pitched for them from 2006-08. Team officials say no deal is done yet, but the Cubs are believed to have interest in Howry as a sixth- or seventh-inning man. He was recently released by the Diamondbacks.
"We've got a much better idea of how to use this bullpen now than we did a month ago," Piniella said. "It's a brand new bullpen. Now we're basically staying almost solely left-handed late in the ballgame, getting to our closer. It's working a lot better."
CUBS 4, PHILLIES 1: Tom Gorzelanny pitched 6 2/3 scoreless innings, giving up three hits. The offense got RBI singles from Starlin Castro and Jeff Baker. Xavier Nady added a two-run single in the ninth. Marmol struggled with his control, but he earned his seventh save.
--Zambrano is scheduled to pitch a simulated game Monday, an off day for the Cubs. After a brief stint as a reliever, Zambrano is being eased back into the rotation, and the Cubs want to build his stamina. Zambrano had to come into Wednesday's game in the eighth to put out a fire, which he did by retiring the only batter he faced.
--Gorzelanny had to leave the game in the bottom of the seventh inning. A comeback liner by Carlos Ruiz caught Gorzelanny on his left hand. Gorzelanny had an X-ray of his left ring finger, and the Cubs said the X-ray was negative.
"I should have caught it," Gorzelanny said. "I didn't want to come out, but I couldn't feel my finger. We'll get some treatment tomorrow and go from there."
Gorzelanny had tossed 6 2/3 shutout innings.
--Baker made his first start in two years in right field. Piniella promised Baker some playing time, but Baker has been crowded out of the infield picture with the recent call-up of Castro and the move of Ryan Theriot to second base. Baker struck out twice and had an RBI single.
--Castro picked up two singles and had an RBI. He also got picked off first base and made a huge defensive play, going to the hole to throw out Jayson Werth to end the eighth with a runner on second. Castro has reached base via a hit or walk in 11 of his first 12 big-league games, hitting safely in 10.
--Aramis Ramirez continues to struggle despite a game-winning homer in extra innings earlier this week. Ramirez went 0-for-4 with two strikeouts, including one with runners on first and second and nobody out in the ninth inning. Ramirez is batting .167 with 35 strikeouts in 150 at-bats. Last year, he struck out 43 times in 306 at-bats. Ramirez has been slow to warm to new hitting coach Rudy Jaramillo, and he was dropped from fourth to fifth in the order Wednesday.