DeRosa, Cedeno battling injuries

NEW YORK - One of the Cubs' most valuable players probably won't play for the rest of the regular season.

Infielder-outfielder Mark DeRosa suffered a strained left calf Wednesday, forcing him from the game. A day later, he was wearing a boot and was limping around the clubhouse.

"Here we go, where we've been pretty healthy for the last month or so, and in one day, we lose two middle infielders," said manager Lou Piniella. "That's not good. I don't know if DeRosa will be able to play at all the rest of the way. We're a little short in the middle."

In addition to DeRosa, infielder Ronny Cedeno was supposed to start at shortstop Thursday, but he had to be replaced by Ryan Theriot.

Cedeno jammed his right shoulder while diving into first base trying for an infield hit. Diving into first is something Lou Piniella would just as soon not see.

"We don't encourage that," Piniella said. "All you're doing is looking for problems. I don't think you get there any faster, either."

Howry impresses: Lou Piniella was happy with how reliever Bob Howry pitched out of a ninth-inning jam Wednesday, allowing the Cubs to win in the 10th. Howry's playoff status has come into question.

"I've been resting Bob as much as I can to get him as strong as we possibly can," Piniella said. "Hopefully, it works. I like Bob. Bob is a no-excuse guy. He 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's immune from them. I like his experience, too. Notice that I've been pitching (Jeff) Samardzija as much as I can in late-inning situations, getting a real good feel for that. Basically, he's holding his own."

Pitching plans: The Cubs are undecided about Sunday's starter in Milwaukee. It could be Sean Marshall. It's possible Carlos Zambrano could pitch out of the bullpen, even if for a couple of innings.

"It would be nice to get him a little work," Lou Piniella said, noting that Zambrano has struggled in his last 2 starts. "A couple innings is all I'm talking about."