"We've got to be very careful with it," Cubs manager Lou Piniella said on Thursday.
DeRosa, who has started 80 games at second base and 32 games in right field, was wearing a boot on his left leg as he hobbled around the clubhouse on Thursday. He has set personal highs this season with 21 homers and 87 RBIs.
"We'll give [Kosuke] Fukudome a little work at second," Piniella said. "He was an infielder."
The Japanese media around Piniella looked at each other.
"No, no -- I'm just joking," he said.
However, the Cubs are not only minus DeRosa but also Ronny Cedeno, who has a strained right shoulder -- suffered when he slid headfirst into first base on Wednesday. Ryan Theriot was supposed to get Thursday off, but he was in the lineup.
"We don't encourage that," Piniella said about sliding headfirst. "All you're doing is looking for problems. I don't think you get there any faster either."
The Cubs have been relatively injury-free in the final days of the regular season. Chicago opens the National League Division Series on Wednesday at Wrigley Field, and general manager Jim Hendry said the decision on the final playoff roster will likely be made on Saturday or Sunday.
One thing the Cubs may do is send some of the players who don't make the NLDS roster to Mesa, Ariz., to continue to work out as a sort of taxi squad. Hendry was leaving the pitching decisions to coach Larry Rothschild.
One pitcher the Cubs are counting on is Bob Howry, who looked sharp in his one inning of work on Wednesday.
"I've been resting Bob as much as I can, trying to get him as strong as we possibly can," Piniella said. "Hopefully, it works. I like Bob. He's a no-excuse guy, and goes out there and pitches and does the best he can. I have all the respect in the world for him. He's had some struggles, but nobody is immune from that.
"I like his experience, too. Notice I've been pitching [Jeff] Samardzija as much as I can in late-inning situations to get a real good feel for that. He's holding his own. It's not the easiest thing in the world for a young guy pitching in these type of situations."
Carlos Zambrano, who did not get a decision in his start on Wednesday, could throw a couple of innings this weekend in Milwaukee as well. Piniella said he wanted to talk to Rothschild and Zambrano first before saying when the right-hander would go.
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.