General manager Mike Rizzo was not available for comment.
Before Tuesday's deadline for posting a bid for the rights to negotiate with Darvish passed, there were doubts Washington would spend close to $100 million on a pitcher without big league experience.
Darvish, 25, is considered an ace pitcher. Last year, he won 18 games and had a 1.44 ERA for the Nippon-Ham Fighters of the Japanese Pacific League.
With Darvish out of the picture, the Nationals are likely to stick with the rotation they currently have, which includes Stephen Strasburg, Jordan Zimmermann, John Lannan, Tommy Milone and fifth-starter candidates Brad Peacock and Ross Detwiler. In fact, Washington's pitching staff ranked seventh in the Major Leagues with a 3.58 ERA.
According to the same source, the Nationals have had little contact with free-agent right-hander Roy Oswalt, who wants a three-year contract. The Nats are all but out of the Gio Gonzalez sweepstakes because, according to another source, the Athletics are "way out of line" in what they want in return.
Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the time. He also could be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.