WASHINGTON -- Entering Tuesday's action, the Nationals are in fifth place and 10 1/2 games behind the Braves in the National League East.

Nationals first baseman Adam Dunn admitted that he doesn't like it when asked if he will be dealt before the Trade Deadline. Dunn is in the last year of a two-year $20 million deal.

Dunn said nothing has been done in terms of getting a contract extension.

"I hear this every single year. This is part of baseball and signing two-year deals that I hate," Dunn said. "There is always a possibility of getting traded, but that is out of my control. I think we have a very good nucleus of guys here. I don't think we need to break up that corps."

General manager Mike Rizzo said the Nationals continue to have interest in signing Dunn to an extension. He said the team is pleased with his offense and defense, which has improved dramatically this season.

"We're looking into it," Rizzo said about Dunn's contract status. "We've been talking about him since Spring Training.

"Like I said, we are looking at every way to improve the club.

"We like where Adam's at offensively and defensively. He's a big part of the clubhouse and a big part of the middle of the lineup."

Nats ponder Trade Deadline options

WASHINGTON -- General manager Mike Rizzo said the Nationals could be buyers or sellers before the July 31st Trade Deadline. He wouldn't get into specifics, but said they are looking to make deals that would help the Nationals in the long term. A year ago, for example, the Nationals traded for center fielder Nyjer Morgan and reliever Sean Burnett and the club was already out of the race.

"If that means buying, we would buy. If that means selling, we will sell. That hasn't changed since Opening Day," Rizzo said.

Rizzo acknowledged that the team's biggest need is starting pitching.

"That's everyone's biggest need and we are included in that," Rizzo said. "We need more starting pitching. Premier, front-line starting pitching is what everybody needs to get to the next level of championship-caliber clubs. We are no different."

Zimmermann has simulated game

WASHINGTON -- Nationals right-hander Jordan Zimmermann, on the disabled list because of elbow reconstruction, had his second simulated game and pitched two innings without any problems.

General manager Mike Rizzo said Zimmermann is expected to start his rehab assignment in a couple of weeks.

"Zimmermann is, according to his rehab calendar, probably a couple weeks away from going on a rehab start," Rizzo said. "We haven't thought about where he is going to go."

Tuesday could be bullpen game

WASHINGTON -- With left-hander John Lannan in the Minor Leagues, the Nationals need a pitcher for next Tuesday against the Braves in Atlanta. Washington is thinking about using a bullpen-by-committee using right-handers Miguel Batista, Joel Peralta and left-hander Sean Burnett. The club also hasn't ruled out calling up right-hander Craig Stammen or left-hander Matt Chico for the start.