The two were paired together after shortstop Cristian Guzman was placed on the disabled list April 3 with a left hamstring strain. Lopez was switched from second to shortstop, his natural position, while Belliard, slated to be a backup infielder, was given the starting nod at second.
"It has been great. You have seen Lopez's plays in the hole ... he has been an All-Star shortstop, and Belliard can turn the double play with anybody," general manager Jim Bowden said.
Both Belliard and Lopez said they are not surprised they have been a good tandem. Both call communication the key.
"He knows what to do at second," Lopez said. "I've played short and I know what to do there. We were both All-Stars at what we do. He is easy to work with."
Said Belliard, "We just react. There is nothing we need to work on. We both have the same approach as far as a double-play combination. It's easier when we talk."
With Guzman not expected back any time soon, are the Nationals willing to stick with the Belliard/Lopez combination all year, or will Guzman be back at shortstop when he returns?
"We are committed to the best team on the field that we can," Bowden said. "That's what we are committed to. And [manager] Manny [Acta] is going to manage the team with the talent that he is given with the best of his abilities, and he makes those decisions."
Just for tonight: Acta decided to sit right fielder Austin Kearns on Tuesday night in favor of Robert Fick. Acta said the move had nothing to do with Kearns' four hits in his last 24 at-bats. The skipper said he wanted to give Fick some at-bats and put another lefty hitter in against Atlanta starter John Smoltz.
"Fick is a very important part of our team, and I need to keep him involved and give him some at-bats," Acta said.
Both Acta and hitting coach Mitchell Page said they are not worried about Kearns, because he has been hitting the ball hard -- though often right at somebody. Page said he is happy Kearns is no longer pull-happy like he was for most of his time with the Nationals in 2006.
"He is swinging the bat real good. I'm happy with him. He should be hitting .320 or .350." Page said.
While Kearns acknowledged he is a little frustrated about not getting the results, he is pleased by the way he is swinging the bat.
"The biggest thing is to stay on top of the ball and use the whole field. You can't get in a pull mode and try to hit the ball out of the ballpark," Kearns said.
Casto heading down: After the Tuesday's game, the Nationals announced they will option left fielder Kory Casto to Triple-A Columbus and purchase the contract of outfielder Michael Restovich from the Clippers on Wednesday.
Washington's bench is overloaded with left-handed hitters, and the team hopes Restovich can provide power from the right side of the plate.
Casto was promoted to the big leagues after center fielder Nook Logan was placed on the disabled list on April 3, but Casto never could find his hitting stroke and was benched last week in favor of Chris Snelling.
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Stat of the day: Entering Tuesday's action, games involving the Nationals have averaged two hours and 48 minutes.
Did you know: Catcher Brian Schneider began Tuesday with five RBIs without getting a hit. The last player to collect five RBIs without a hit was Pirates outfielder Mike Kingery in 1996.
Coming up: The Nationals return to RFK to start a two-game series against the Phillies starting Wednesday night at 7:05 p.m. ET. Washington right-hander Jason Bergmann will face Philadelphia right-hander Adam Eaton.
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.