Aside from Rodriguez, Rizzo did not mention any specific names. But the relievers most likely to draw realistic interest are Tyler Clippard, Drew Storen, Todd Coffey and Sean Burnett. In the rotation, the Nationals could part with Jason Marquis, Livan Hernandez and/or Tom Gorzelanny.

“I would probably describe it as moderately busy,” Rizzo said. “We’re fielding more calls than we’re making. The business has been pretty brisk. It’s not probably as busy as we’ve been in the last couple years. Not anything more than that.”

Rizzo maintained his stance that the Nationals will be sellers in regard to 2011 but also actively looking to add pieces that could help them this season and beyond. “I don’t know any other way to be,” Rizzo said. “If you can make a trade to better yourself long-term – again, we’re not going to be buyers to buy for 2011 only. If we’re buyers, it’ll be a long-term asset that will help us this year and down the road. We could also be sellers, too.”

The Nationals, a team source said, remain focused on acquiring a center fielder who can hit leadoff, but there is also a “limited market” for that kind of player, the source said. The Nationals’ deepest area is their bullpen, but trading one reliever – even Storen, a closer under team control through 2016 – would not likely return the kind of player the Nationals want as their long-term center fielder and leadoff man. (Then again, Matt Capps last year netted the Nationals Wilson Ramos, who could feasibly be their catcher for the next decade.)

Rizzo said no Nationals player will be “untouchable,” but he also said “we’re not going to touch our core” – players such as Danny Espinosa, Ryan Zimmerman and Ramos.

“We got calls early on a lot of players, and we kind of dismiss a lot of them,” Rizzo said. “After a while, they don’t ask for Espinosa.”

The Nationals have improved their minor league depth through the draft in recent seasons, which could have an effect at this year’s trade deadline. “You always trade from depth and strength,” Rizzo said. “We feel that we’ve put together some depth at certain positions.”

One example: With middle infielder Stephen Lombardozzi playing well at Class AAA Syracuse, and infielder Anthony Rendon having been drafted with the sixth overall pick this year, the Nationals could be more willing to part with shortstop Ian Desmond.