The Nationals are back at home for a three-game series against the Marlins before heading back out on the road against the Mets and Orioles. Some news:

* Elijah Dukes and Jesus Flores joined the team today, though neither one is in the lineup tonight. Dukes, however, had some interesting things to say. He said his hamstring is 100 percent, and while he admits he'll have to work at coming off the bench, he doesn't think he'll be there long. "They don't need to look at me for that answer. They need to look moreso at the organization and just the players in front of me, not what I can do," he said. "I know what I can do on the field. It ain't on me about how much I want to play and stuff. I want to play, so I'm just waiting for my chance to get out there and do what I do."

And on his ejection last Sunday after arguing balls and strikes with umpire Jason Klein following his second called strikeout of the game: "I don't know. I was just tired. He was calling some BS calls. I said what I said and he threw me out, so whatever."

* The Nationals traded for minor-league catcher David Wallace before the game, sending a player to be named to Cleveland. Wallace will join Columbus tonight, presumably to fill in for Flores while he's in the big leagues. Wallace, 28, has never played in the majors.

Here's the lineup:

Felipe Lopez 2B
Cristian Guzman SS
Ryan Zimmerman 3B
Nick Johnson 1B
Lastings Milledge CF
Austin Kearns RF
Wily Mo Pena LF
Wil Nieves C
Tim Redding P

The Nationals will place both Paul Lo Duca and Johnny Estrada on the 15-day DL tomorrow and probably won't have either of their veteran catchers available for a while.

An MRI taken today on Lo Duca's right hand revealed a fracture of the fourth metacarpal bone. It probably was already slightly broken weeks ago when Lo Duca was hit in the hand by a pitch and landed on the DL for the first time, then was made worse last night when he fouled off a pitch in the seventh inning and recoiled in agony. The club says he's likely to miss four to six weeks, though that's a very rough estimate.

Estrada, meanwhile, is headed back to the DL also with ulnar neuritis in his right elbow. Basically, the surgery he had during the offseason to repair the elbow hasn't worked and possibly even made it worse. Estrada said he's talked to a few other players who have had similar injuries who said it took them a year to fully recover, though he remains confident he'll be back to play this season.

Who replaces those two? Jesus Flores will be recalled from Class AAA Columbus tomorrow and will become the regular starting catcher, with some help from Wil Nieves. Elijah Dukes also will be activated off the DL and will be available for the first time since straining a hamstring on Opening Night.

The Nats' starting lineup for tonight's game against the Astros has been published, and it contains a few surprises...

CF Willie Harris
SS Cristian Guzman
3B Ryan Zimmerman
1B Nick Johnson
RF Austin Kearns
2B Ronnie Belliard
LF Rob Mackowiak
C Wil Nieves
P John Lannan

So Lastings Milledge and Wily Mo Pena each get the night off, which could help the Nats' outfield defense (though it may not help the offense much). Also, Ronnie Belliard gets his first start since April 20.

Paul Lo Duca's having an MRI today on his right hand, which he re-injured last night fouling off a pitch against the Astros. Lo Duca, as you already know, spent two weeks on the DL last month after getting hit by a pitch on that hand. He admitted that it had still been sore in recent days and was really bothering him during last night's game.

When he fouled off that last pitch from Roy Oswalt in the seventh inning, "I just felt a really, really, really sharp pain," he said. "Probably the most pain I've ever felt."

We'll have to see what the MRI says, but it certainly would appear that Lo Duca is headed back for the DL. Which means Wil Nieves probably becomes the starting catcher, with some help from Johnny Estrada (who still has trouble throwing because of his own right elbow injury). The other irony: Lo Duca will probably miss the Nats' series in New York for the second time in two months, depriving Mets fans their opportunity to serenade their former catcher with either cheers or boos.

The other strange part of the Lo Duca injury last night happened as he was walking back to the dugout. A group of three rowdy fans, who apparently had been harrassing Nats players from the start of the game, called Lo Duca a not-so-nice word that I couldn't use in the paper. I paraphrased it into "wimp." Lo Duca, his hand obviously in agony, couldn't hold it in and started yelling back at the guys.

"The guy was being obnoxious the whole night," he said. "I just kept my mouth shut and didn't say anything. Then I'm coming off the field and he told me I was a [wimp]. So I said: 'If I'm a [wimp], come outside and wait for me.' He turned red as a freaking ketchup bottle."

Wow, what an exchange. Anyways, security personnel quickly came over and escorted the three guys out of the ballpark. A strange, surreal scene to say the least.

In the bigger picture, the Nats have lost two straight heartbreakers to the Astros and could really use a well-played, clean win tonight. John Lannan vs. Brandon Backe at 8:05 p.m.

Finally, a heads-up for fans who are planning to take Metro to this weekend's games against the Marlins. This is straight from a press release issued by the Nats:

"The Metrorail Green Line will undergo temporary track work on Saturday May 10 and Sunday May 11 that will delay fans' post-game ride from the ballpark. Metro will provide complimentary bus service from Nationals Park to Federal Center Metrorail Station (Blue/Orange Line), Eastern Market Metrorail Station (Blue/Orange Line) and Union Station (Red Line). Fans may drive to Nationals Park and purchase single game parking at Nationals Park Lots or park free at RFK Stadium and take the free Nats Express to the ballpark."

Paul Lo Duca had to leave tonight's game in the seventh inning after fouling off an 0-1 pitch from Roy Oswalt and then screaming out in agony. No official word yet from the Nationals, but it appeared as though Lo Duca re-injured the right hand that put him on the DL last month.

The scene turned really strange when Lo Duca, as he was walking back to the dugout, started yelling and pointing at a couple of fans in the first row who were razzing him. Lo Duca nearly had to be restrained by assistant trainer Mike McGowan before going down the dugout steps and retreating to the clubhouse.

Stadium security then escorted three men from the front row out of the ballpark.

Meanwhile, it's still 3-3 in the eighth inning of another wild game.

Ryan Zimmerman has taken Roy Oswalt deep twice tonight. Everyone else in a Nats' uniform? 2-for-18 with eight strikeouts.

Still, the Nats and Astros are tied 3-3 in the bottom of the sixth.

Mike O'Connor is now on in relief of Odalis Perez, but don't get worried. O'Connor still will start Saturday against the Marlins. Today would have been his normal day to throw in the bullpen, so the Nats are just using the game as an opportunity for him to get his work in. O'Connor won't pitch more than one inning, I can assure you.

As you heard earlier, the Nats have demoted Matt Chico to the bullpen and named Mike O'Connor Saturday night's starter against the Marlins. Didn't sound like it was a particularly difficult decision for Manny Acta and Co. Chico (0-5, 6.87) simply wasn't giving his team a chance to win and he admitted he was "pressing" and getting out of his game. Perhaps he can sort some things out in the bullpen now.

Here's what the pertinent parties all had to say about the switch...

MANNY ACTA
On the decision: "We just want to release Matt from some of that tension that he's having every five days going out there. And we want to give O'Connor a shot. He pitched well at Triple-A, and we still see him as a starter."

On Chico: "He's having some trouble right now every five days and he understands that. He admitted that he's been pressing a little bit out there, and this is going to be an opportunity for him to step away from that."

On O'Connor: "I can't wait to see him. And probably it's not going to be a one-start type of thing, because we don't know how he's going to go out there the first time."

On not promoting Jason Bergmann from Columbus: "Every one of those guys were in the mix. But we felt that Chico being lefty just like O'Connor, it's a little bit of an advantage to have a lefty in the pen."

MATT CHICO
On the demotion: "I was gripping the ball way too tight, trying to make that perfect pitch, and ended up leaving balls over the middle. I think just the change of scenery ... hopefully it's going to help me get back to where I want to be and get back to the starting rotation."

On "pressing": "When I was starting, I was trying to do too much. I was trying to throw five wins in one game. And now it's a different role, a different idea of going out there, going out there trying to save runs."

MIKE O'CONNOR
On returning to the rotation: "I'm excited for the opportunity to start again. It's what I've been doing in the past. At this point, I feel a little more comfortable starting."

On 2006 vs. 2008: "I think I've gotten a little better from then. It's still a big deal, but I'm not going to lose sleep over it like I did the first time."

Mark Zuckerman just phoned this in: Mike O'Connor will get the start for the Nationals on Saturday against the Marlins, with Matt Chico getting sent to the bullpen.

Mark will be back soon with more details. ...

Odalis Perez takes the mound again tonight for the Nationals, which means two things:

1. Perez will almost certainly pitch well enough to give his team a chance to win.

2. He almost certainly won't earn the win himself.

Is their a harder-luck pitcher in baseball right now? I mean, Perez has a 3.18 ERA in seven starts. He's allowed two or fewer runs in six of those outings. He's produced four straight quality starts. And his record is 0-3.

It's pretty remarkable when you think about it. Even on a bad-hitting team, you'd expect a pitcher to get lucky once and earn the W. Not so for Perez, who to his credit refuses to complain about the big zero that follows his name every time he's listed as the starting pitcher.

"Everyone is trying hard," he said following his last start, a 3-2 loss to the Pirates. "I'm happy to go out there every five days and go six, seven innings. If I don't get the win, if I pitch good, I feel good."

Perhaps tonight will finally be the night, though Perez and the Nats certainly face a daunting challenge. Not only does he need to pitch well against an Astros lineup that is tearing it up (see: Berkman, Lance) but he also needs his teammates to make a dent into a guy named Roy Oswalt. Oswalt's career numbers against the Washington franchise: 3-1, 2.45 ERA in 6 starts, 39 total baserunners allowed in 47 2/3 innings.

Anyone heard of the "Reverse Lock" theory?

Washington Times columnist Thom Loverro will be on The Sports Reporters today on SportsTalk 980-AM WTEM from 5 to 7 p.m, talking Nationals and other subjects.