While McLaren declined to talk about his future, a baseball source indicated that McLaren wanted to leave the organization, but was talked out of it by Rizzo. McLaren was Washington's bench coach until Jim Riggleman resigned as manager on Thursday. Johnson will determine who replaces McLaren as bench coach.
"We are going to reassign him to assist me in scouting and other duties in a non-uniform capacity," Rizzo said of McLaren. "It was a mutual decision. He has an allegiance to Jim. He had some thoughts about getting out of uniform and trying something different."
This will be Johnson's fifth managerial stint. He skippered the Mets, Reds, Orioles and Dodgers and went a combined 1,148-888 with one World Series title with the Mets in 1986. The last time he managed in the big leagues was in 2000, with the Dodgers.
Johnson is expected to manage Washington through 2012, according to a baseball source, with an option for the '13 season. He'll make his Nats debut on Monday against the Angels. Before an announcement is made, Johnson and the Nationals have to agree on contract language.
"We have a few technical things to figure out before we can make any announcement," Rizzo said. "I'm going to hold off on talking about Davey. ... It's contract language. It's dotting the I's and crossing the T's type of stuff. There is no signed document yet, so we want to make sure we have our ducks in a row and everything in place before [we make an announcement]."
Johnson has joined the club in Chicago, but he will observe the players from a distance until Monday.
Johnson, 68, had been a senior advisor to Rizzo and he will take over a team that has improved dramatically from last year. Entering Saturday's action, the Nationals were 39-37 and only 3 1/2 games behind the Braves for the National League Wild Card.
Once he takes over, Johnson will become the second-oldest manager behind Marlins skipper Jack McKeon, who is 80 years old.
Johnson played 13 seasons in the Major Leagues for the Orioles, Braves, Phillies and Cubs, hitting 136 home runs in 1,435 games. His best season was 1973 with Atlanta, when he tied Rogers Hornsby's record with 42 home runs as a second baseman, hitting a 43rd as a pinch-hitter.
Johnson has managed in international play for the Netherlands and the United States. He was at the helm for Team USA during the 2008 Olympic Games, when his roster included Nats ace Stephen Strasburg.
Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the time He also can be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.