DeRosa injured his hand Monday in a freak collision with Endy Chavez, who was running to first base. DeRosa, playing first in place of Derrek Lee, underwent an MRI on Wednesday which revealed the sprain of the volar plate, which is located in the palm of his hand.
"It's something that sounds probably a lot worse than it is," DeRosa said Wednesday. "I went for an MRI today and I have a tear or something in there, but it's not something to be concerned about. It's just a matter of what type of pain threshold I can deal with."
DeRosa planned to take some dry swings, and hopes he can play on Thursday when the Cubs close their series against the New York Mets.
"I don't see how it will keep me out for long," he said. "I definitely did some damage to it."
DeRosa will have to wear some kind of pad on his hand, because the sore spot is right where the bat handle lays in his hand.
"It's another one of those freak things that has happened to me in my career," he said. "Hopefully, it won't keep me out much longer."
"In a player's defense, when something goes wrong in the hand area, it makes things a little more difficult," Cubs manager Lou Piniella said. "To what extent of discomfort he has, I guess we won't know until he hits live pitching or live batting practice. You hurt your hand, your wrist, that area, it makes things more difficult."
The Cubs did add infielder Mike Fontenot on Tuesday, but are playing shorthanded with Lee still in Chicago because of neck spasms. Lee will rejoin the team Friday when it opens a weekend Interleague series against the White Sox.
"It's tough on them," DeRosa said of the team. "They're trying to save me, but at the same time I'm costing them a roster spot. Last night, I probably could've gone in for [Aramis Ramirez]."
Aches and pains: Lee's condition has improved, but the Cubs medical staff decided it was better to keep the first baseman in Chicago rather than have him fly to New York.
"He's better today, and we feel that by keeping him there, by Friday, he could possibly be ready," Piniella said.
Lee still leads the Major Leagues with a .390 batting average.
Leadoff man: Ryan Theriot would appear to be well suited for the leadoff role.
"It's a spot I'm comfortable in, and hopefully I can do a number of things to help the team out there," said Theriot, who was batting .357 (10-for-28) in six games in the leadoff spot so far.
Theriot has done better with more playing time. He hit a very respectable .299 in April, and was hitting .333 in May.
"Early on, I wasn't getting consistent at-bats," Theriot said. "I'd get in in the seventh, eighth innings and I was getting one at-bat. You really don't want to take pitches at that point because the guy will throw you fastballs and you go up there hacking. My main focus is getting the guy behind me up to the plate, whether it's Cliff [Floyd] or D-Lee or whoever it is. Those are the guys paid to drive them in. It's tough to drive runners in when nobody's on base. That's my focus, to get a hit, a walk or reach on an error.
"I think it's a spot I can really excel at. I feel real good in the two-hole as well. Any time you go up and have a plan and a purpose, it always makes it easier."
He may stay there if Piniella decides to move Alfonso Soriano to second. That's OK with Theriot.
"I'm just trying to get on there for the boppers," he said. "I want the guy behind me to have 100 RBIs, and I want to score 100 runs. That's how you win games -- touching home plate the most. I want to be the guy to do that, touching home plate."
Cherry pie: Rocky Cherry needs to figure out what he was doing in March to get called back to the big leagues. The right-handed reliever was optioned to Triple-A Iowa on Tuesday to make room for Fontenot. The Cubs wanted an extra infielder with DeRosa bothered by a strained finger on his right hand.
"Rocky got a taste up here, and he needs to go down there and get to throwing the ball like he did in Spring Training for us," Piniella said. "In Spring Training, he had a real nice 92, 93 mile-an-hour hard sinker, he had a nice little tight slider with some depth to it, and for whatever reason, he's gotten away from that. He needs to go down there and find it.
"He got some experience up here, and basically he toughed it out. By his admission, he knew he didn't have the stuff he had this spring. He's a tough kid. He'll be back."
Cherry was 1-1 with a 2.89 ERA, and limited batters to a .235 average. He held opponents scoreless in six of his eight appearances.
Extra bases: The Cubs already have more wins this month than they did in May 2006, when the team won seven. ... Timing is everything. The Cubs were batting .408 with runners in scoring position (20-for-49) over their last four games. That follows an 0-for-17 stretch that began May 8 vs. Pittsburgh. ... The Cubs will play the April 11 postponed game against Houston on June 11 at 7:05 p.m. CT at Wrigley Field. Tickets to the April 11 game are not valid for the makeup game.
Minor matters: Mike Kinkade hit a two-run homer in the bottom of the 10th to give Iowa a 6-4 victory over Sacramento on Tuesday. Les Walrond gave up three runs on eight hits and seven walks over six innings. Kinkade was 3-for-5. ... Wade Miller gave up three runs on seven hits over 5 2/3 innings in Double-A Tennessee's 6-4 win over Chattanooga. Donnie Veal earned the win, pitching in relief. It was Veal's scheduled start day. Jake Fox hit his second homer in as many days, going 4-for-4. ... Mitch Atkins gave up one run, unearned, on four hits over seven innings in Class A Daytona's 2-0 loss to Vero Beach. ... Italian pitcher Alessandro Maestri gave up one run on three hits over four innings in his first start, and did not get a decision in Class A Peoria's 3-1 win over Beloit. Josh Lansford had two hits.
On deck: Right-hander Angel Guzman will close the four-game series in the Big Apple on Thursday when he makes his third start. The game, scheduled for 12:10 p.m. CT, will be broadcast on WGN TV and WGN Radio, and can also be followed on MLB.TV or Gameday Audio.
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.