DENVER -- Of the Nationals' top five picks in the 2008 First-Year Player Draft, four of them -- right-hander Aaron Crow, shortstop Daniel Espinosa, left-hander Graham Hicks and catcher Adrian Nieto -- are unsigned.

Major League teams have until Aug. 15 to sign players taken in the Draft.

Destin Hood, a second-round pick, signed with Washington on July 17 and will make a total of $1.1 million over the next five years. That sum of money is considered to be a little over the baseball slotting system, when it comes to second-round picks.

Nationals president Stan Kasten acknowledged on Tuesday that the team most likely will not sign all of its top picks. Kasten declined to say which players he felt were unsignable. However, late last week, general manager Jim Bowden said negotiations with Crow, the Nats' top pick, weren't going well. Crow is represented by advisor J.D. Smart, who works for the Hendricks brothers. Smart was not available for comment.

The Nationals feel that Crow's salary should be similar to what pitcher Ross Detwiler received. Detwiler, the team's first-round pick in 2007, received a $2.15 million signing bonus.

"The Crow case is a little interesting. In some respects, that decision is easier than all. It's kind of pretty well determined," Kasten said. "We know what the Chad Corderos, the Ryan Zimmermans, the Chris Marreros and the Ross Detwilers received. We know what their value is. We know what the No. 10 pick [in the first round] is already getting. The feeling is, [regarding Crow] it's between No. 10 this year and what Detwiler's contract was. That's the appropriate value. It's fairly easy to figure out."

Kasten said the organization will have an idea by next week on who it will sign before the deadline. Overall, the Nationals have signed 25 out of their 50 picks thus far.

"I'm sure we'll sign some more of our picks, but I don't think we will sign all of them, but we will try," Kasten said. "We studied this pretty carefully. We decide the value that we place on prospects. That's the No. 1 consideration. Sometimes it's more than Major League Baseball's recommendations, sometimes it's less than the recommendations.

"It still comes down to what value we place on guys. And to determine that value, we pay close attention to the market activity and comparable signings. We are just not going to pay something ... because extraneous voices decide, 'Well, this is what I decide I have to have.' We are not going to do that."

If the Nationals are unable to sign their top Draft picks, the money slotted for them would most likely go toward signing young players outside the United States.

In fact, Kasten told the Nationals' board of directors right after the Draft that the team would most likely not sign most of its picks like it did last year. He told them it would be similar to the 2006 Draft, when the team didn't sign four of its first 12 picks, including left-hander Sean Black, its second-round pick.

This year's Draft is in sharp contrast to last year's for the Nationals. In 2007, the Nationals signed their first 20 picks. They even went over the slotting system to sign pitcher Jack McGeary, a sixth-round pick who signed first-round money.

"[The 2008] Draft felt like one of those years where we wouldn't sign all of our top picks, which is like a normal year. Last year was an aberration," Kasten said. "This Draft has felt [different] to me, because of the kind of guys we drafted and some of their circumstances, and I think that's how it's playing out.

"Last year, we were among the leaders in amateur signing bonuses. We are prepared to do that this year, but we are not going to do unreasonable contracts."