Trachsel, acquired Friday from the Baltimore Orioles for two Minor Leaguers, will start the second game of the Cubs' four-game series against the Dodgers. Carlos Zambrano will open on Monday, and Ted Lilly and Jason Marquis will pitch Wednesday and Thursday, respectively.

Sean Marshall is the odd man out, getting skipped one time in the rotation. He'll go to the bullpen, beginning Monday. As for what the Cubs will do rotation-wise for the weekend trip to Pittsburgh, it's to be determined.

"Let's leave it at this for now, and then we can make up our minds," Cubs manager Lou Piniella said.

Marshall was OK with the news.

"I'll do whatever we need to win," said the left-hander, who is 7-7 with a 3.98 ERA.

"We've skipped people here from time to time this summer," Piniella said. "We traded for Trachsel. He's had experience in these type of situations. It gives us innings in the bullpen from the left side, which we haven't had all summer. At the same time, we give Marshall a little breather."

Marshall has pitched in 18 games with the Cubs, totaling 97 1/3 innings. He totaled 125 2/3 innings last season with the big league team, and pitched another 21 2/3 innings in the Minors.

In his last outing against Houston on Friday, Marshall lasted 3 2/3 innings. He threw on the side Sunday, and has some mechanical adjustments to make.

"I'm striding across my body, striding toward first base too much, and it's causing me to jerk, and I was jerking the ball a little bit," he said. "Instead of throwing in a straight line, I was throwing in a circle. I've got time to work on that and get ready for my next appearance."

So, maybe the time on the side will benefit him?

"It's not that big of a thing," Marshall said. "I'll just iron it out and be ready to go."

Trachsel should have new shoes by Tuesday. He was wearing his Baltimore Orioles cleats on Sunday, and the black and orange definitely clashed with his Cubs uniform. Maybe someone on the team who wears a size 11 can loan him a pair.

Tweaks: Add Kerry Wood to the list of late-inning options for Piniella, joining Bob Howry and Carlos Marmol.

In 10 games so far, Wood has a 3.18 ERA, giving up four runs on eight hits and striking out 10 over 11 1/3 innings. Putting Wood in the mix will ease some of the workload on Marmol.

"We've brought him along," Piniella said. "He's starting to throw the ball better and he's got that experience also."

Marmol boasts a 1.46 ERA in 47 games, best among the relievers.

"Since we've had him in the bullpen, it's changed the look of it," Piniella said of the hard-throwing right-hander. "It's given us a power pitcher. He's done a really nice job. I don't know where we'd be without him."

It's hard to believe Marmol once was a catcher.

"Whoever made the suggestion [to convert him to a pitcher], made a wise one," Piniella said.

Small ball: Some of the pitchers were working on their bunting early Sunday. Mark DeRosa wasn't in the group.

DeRosa was unable to execute a bunt Saturday in the eighth inning with runners at first and second, and Aramis Ramirez was picked off second base.

Piniella blamed a lack of concentration. DeRosa said that wasn't the case.

"It just didn't happen," DeRosa said. "I apologized to Ramy. He looks like he's in a bad position and bad baserunning. I know he has a knee that's bad, and I know my bunt has to be perfect. He knows he has to get a perfect lead. He's assuming I'm going to get it down, and I hung him out to dry in that situation. It's my bad. I take full responsibility for that. The bunt's got to get done.

"It's not like I got caught off guard by the call -- I knew it was coming," DeRosa said. "But it's not for lack of concentration. No one concentrates harder."

Bunting looks easy. Why can't the Cubs do it?

"Bunting should be the easiest thing in the game to do, but it's not practiced much," DeRosa said. "I think it's one of those things you put too much pressure on yourself to try to be too perfect."

Coach Ivan DeJesus has been working with the pitchers and position players on bunting this season, but he has been absent after needing surgery for prostate cancer. The procedure went well, and DeJesus should be back with the Cubs in a week to 10 days.

"He's doing fine," Piniella said.

Bench coach Alan Trammell will work with the hitters on bunting until DeJesus returns.

"It's important for us because we use it to try to tack on runs," Piniella said. "We've done a good job all year. Just in the past two or three series, we haven't executed. It makes a difference."

Extra bases: Ron Santo got a new prosthetic Saturday to replace his artificial left leg, which had a broken socket and forced the WGN Radio commentator to leave the game in the sixth inning. "I had an equipment problem," Santo said. ... Sunday was the last game at Wrigley Field for Houston's Craig Biggio, who is retiring at the end of the year. The Cubs players presented Biggio with a No. 7 from the Wrigley Field scoreboard, and the classy infielder signed a bat for Wood. Biggio was in the Astros lineup May 6, 1998, when Wood struck out 20, tying a Major League record. Biggio's message to Wood on the bat: "The single most dominant game I've ever seen." ... Alfonso Soriano has passed all tests with his leg. He made a heads-up baserunning play Saturday, scoring from first on Ryan Theriot's double and an error. "Sometimes our offense needs to be jump-started, and he jump-started it," Piniella said. ... Instead of going to Peoria for a rehab assignment, outfielder Angel Pagan went to Mesa, Ariz., to work out at the Cubs' facility there. Pagan is on the disabled list with colitis. ... Trachsel saves jerseys from all of the teams he's played for, and had four Orioles jerseys stuffed in his gear bag as souvenirs.

Minor matters: J.R. Mathes gave up six earned runs on eight hits over 4 1/3 innings in Triple-A Iowa's 8-1 loss to Omaha on Saturday. Koyie Hill had two hits. ... Donnie Veal gave up two hits over five innings in Double-A Tennessee's 7-4 win over Carolina on Saturday. He struck out eight. ... Class A Daytona's game Saturday was postponed by rain, and was to be made up as a doubleheader Sunday. ... Jeremy Papelbon gave up one run on six hits over five innings in Class A Peoria's 4-2 win over Cedar Rapids on Saturday. ... Short season Boise beat Spokane, 8-5, on Saturday, scoring seven runs in the last three innings.

On deck: Carlos Zambrano will try to end his winless streak on Monday when he takes the mound for Game 1 of a four-game set against the Los Angeles Dodgers at Wrigley Field. Big Z was 0-for-August, going 0-4 with a 7.06 ERA in five starts. First pitch is scheduled for 3:05 p.m. CT, and the game will be broadcast on WGN.

This story was not subject to the approval of Major League Baseball or its clubs.