VIERA, Fla. -- The Nationals decided Wednesday that their general manager's position will remain vacant for the foreseeable future.

Team president Stan Kasten will remain the person in charge, but assistant GM Mike Rizzo will have principal responsibilities when it comes to the Major League, Minor League and scouting operations. All team matters or inquiries will be directed to Rizzo, with Kasten working closely with him.

Bob Boone will continue to be an assistant GM in charge of the Minor Leagues, while Dana Brown will remain the scouting director. Both men will report to Rizzo.

"The owners have confidence in Mike in getting the job done on the duties relating to the Major League team," Kasten said. "Together, he and I will handle that for now. ... We have confidence in Mike taking on an additional new role, additional responsibility in this area. As we have seen, he is a can-do guy. When you challenge him, he steps up like all the people on our staff."

The Nationals will continue to search for a GM, but they believe they are in good hands with Rizzo. The team has been without a GM since Sunday, when Jim Bowden resigned.

"We are going to let the GM position remain vacant," Kasten said. "I do intend to be a lot closer to the operation in the coming weeks and months.

"At some point, I have to do some research and a search [for a GM] will progress, but I don't feel any rush at all. There is no particular urgency or timetable for that. ... We have seen things run smoothly. A little bit of calming rather more change now is what we need best."

Rizzo, 48, acknowledged that he would like to become a full-time GM.

"My goal is to always be a Major League general manager," Rizzo said. "As Stan said, we have a good feel for each other and I think we have a good group put together here with the Nationals. The goal is to succeed and put together the best team possible."

Rizzo is already working on trades. The team needs to solidify the bullpen. As of now, closer Joel Hanrahan and setup man Saul Rivera are the only relievers who have guaranteed spots in the bullpen.

"We are going to look at all the avenues to improve the club for '09," Rizzo said. "Trades, free agents -- we are going to think outside the box. We are prepared to go all avenues."

Rizzo scored valuable points last week when he had the task of moving the Nationals' baseball academy from Jose Rijo's complex in the Dominican Republic to a facility built by Rawlings, the glove manufacturer, in Boca Chica. At the direction of Kasten, the move had to be done in three days, and Rizzo and his staff were able to pull it off.

The team left Rijo's facility after reports surfaced linking Rijo to Carlos Alvarez David Lugo, who previously called himself Esmailyn Gonzalez. The shortstop, who received a $1.4 million signing bonus from the Nationals in 2006, allegedly falsified his name and age. In Washington's 2008 media guide, Lugo is listed as 19, but is really 23.

"Rizzo made it easier than what it really was, but I'm not surprised that he pulled it off. It's what I expected. That's why we sent him there," Kasten said about the job Rizzo did in the Dominican Republic.

Rizzo comes from a baseball family. His father, Phil, is a longtime baseball scout. Mike, who has been in baseball for 27 years, followed in his father's footsteps.

As a White Sox scout, Mike signed first baseman Frank Thomas to his first professional contract in 1989. Thomas had a 19-year career in the big leagues and hit 521 home runs.

Rizzo was a scouting director for the Diamondbacks for almost 10 years and drafted players including Stephen Drew, Justin Upton, Dan Uggla and Brandon Webb. Because of Rizzo's expertise in the First-Year Player Draft, Arizona's farm system was ranked No. 1 by Baseball America in 2006.

Rizzo joined the Nationals on July 24, 2006. Since then, the team's farm system has improved dramatically. They are loaded with pitching prospects, such as right-handers Jordan Zimmermann and Shairon Martis.