Cedeno, who was the Cubs' everyday shortstop last season, struggled at the plate in 11 games this year, batting .097 (3-for-31) with two home runs and four RBIs.
"It's tough on everybody," Cubs manager Lou Piniella said about optioning Cedeno. "Nobody likes to send people out. I know I don't."
This is Guzman's second stint with the team this year after beginning the season on the Opening Day roster. He made four relief appearances, compiling a 2.45 ERA, before being optioned to Iowa on April 17.
Guzman was 0-2 in three starts for the Minor League team with a 12.19 ERA. In his last appearance on May 1 against Nashville, the right-hander struck out two, but gave up seven runs on four hits and four walks in three innings of work.
"I would like to see him go out there and throw the ball and give us a chance to win, [the] same that we expect from all our starting pitchers," Piniella said about Guzman's first start. "If they go into the sixth inning and give our team a chance to win, that's all you can expect."
Outfield shuffle: With Cedeno going to Iowa, rookie Felix Pie stays in the crowded outfield. The only issue is continuing to get him into as many games as possible.
"We'll get Pie in there as we can," Piniella said. "He's been getting in every day [for] an at-bat or two. He's been valuable in that regard, but I've got veteran players that I need to take care of -- and I will -- [to] give them their playing time."
Cliff Floyd is one of those veteran players, but he has not been available because of a back problem. Mark DeRosa made his third start in right field on Sunday. Five different players have played right for the Cubs, but the time has been split primarily between Floyd and Matt Murton.
Piniella has said he wants a constant lineup but it's really only Soriano, Derrek Lee, Aramis Ramirez and Jacque Jones who are set. The others need to check the lineup card every day to see if they're playing. On Sunday, Ryan Theriot, who's batting .320 and matched a career high with three walks on Saturday, started at second.
"I find ways to get Theriot in the lineup because he deserves to be in there," Piniella said. "He's done a really good job, and because of that, I moved things around a little bit. Outside of one position, everything's set."
Right place, right time: Moving to left field may have been the best thing for Soriano. He's batting .364 (16-for-44) in nine games since switching to left on April 23. He was hitting .245 (12-for-49) in 12 games in center field.
"I do enjoy it more, and I'm more comfortable," Soriano said Sunday. "The weather is getting a little warmer, which I enjoy, and if I enjoy it, I'm more relaxed. Maybe [being in left] is contributing, because I'm more relaxed."
Soriano treated his former Nationals teammates to dinner while they were in Chicago. He expects them to reciprocate when the Cubs visit Washington in July.
Extra bases: The Cubs were batting .333 with 20 RBIs with the bases loaded this season. ... The Cubs drew three consecutive bases-loaded walks in one inning on Saturday. The last time they did that was June 19, 1999, in an 11-5 loss to San Francisco. ... Henry Blanco was given the go-ahead to play, although Piniella wanted to give him another day off plus Monday's off-day. Blanco has a herniated disc in his neck. ... Lee did not have final figures on money raised on Saturday for Project 3000 and its fight against Lebers Congenital Amaurosis (LCA), a rare genetic eye disease, but appreciated the fans' contributions. Lee's daughter Jada has partial blindness in one eye from LCA. ... Umpire clubhouse attendant Jimmy Farrell and wife Eleanor celebrated their 63rd wedding anniversary on Sunday. Farrell has handled the umpire's quarters for 25 years.
Minor matters: Eric Patterson went 4-for-5 with an RBI and two runs scored in Iowa's 6-5 win over New Orleans. Patterson is 7-for-9 with three RBIs in his last two games. Les Walrond got his third win of the season, giving up four runs on eight hits over six innings. Clay Rapada retired the final five batters for his second save. ... Donnie Veal won his first game of the season for Tennessee, giving up three hits over seven shutout innings. Matt Craig hit an RBI single in the 1-0 win. ... Todd Blackford gave up three runs over five innings, but did not get a decision in Daytona's 6-3 loss to the Tampa Yankees. Scott Koerber served up a three-run home run in the eighth to take the loss. ... Jose Ceda's record fell to 2-2 after Peoria managed just three hits in a 3-2 loss to Fort Wayne. Jeremy Papelbon and Charles Platt combined for 6 1/3 scoreless innings out of the bullpen.
On deck: After a day off on Monday, Ted Lilly will start Tuesday's series opener against Pittsburgh. Lilly settled for a no-decision in his last start against the Pirates on May 1, giving up five runs, four earned, on nine hits in 5 1/3 innings. It was his shortest outing of the season. Tuesday's first pitch is scheduled for 7:05 p.m. CT.
Marc Zarefsky is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.