The moves mean that left-hander Matt Chico will be the fourth starter in the rotation, Aaron Boone will be one of the backup infielders, Willie Harris and Rob Mackowiak will be the extra outfielders and right-hander Joel Hanrahan will be the seventh man in the bullpen.
Putting Estrada, who has been bothered by a sore elbow, on the DL was not a surprise, especially since he didn't play his first Minor League game until Tuesday. He is expected to be activated in two weeks. Jesus Flores will be the backup catcher for the time being and then be sent to Double-A Harrisburg when Estrada is activated.
Of the four that were sent to the Minor Leagues, Lannan and Orr had great springs.
Lannan was a strong candidate to be in the rotation. He had a 2.45 ERA in four starts, and some members of the think tank wanted Lannan to be in the rotation, according to a source. But loyalty won out for Chico. Manager Manny Acta and pitching coach Randy St. Claire respected the fact that Chico was the team's only pitcher who never missed a turn while he was in the big leagues last year.
What also helped Chico was that he improved his pitching as the spring wore on. He went back to a high-leg kick, which added extra velocity to his fastball. Acta didn't rule out Lannan pitching for the big club on April 13 against the Braves. Right-hander Shawn Hill might not be ready to pitch if he continues to have right forearm problems.
"The Lannan situation -- he understands [what's going on]," Acta said. "He might be here pretty soon, depending on what happens with Shawn Hill. It's a sign of progress. It gives us a chance not to rush anybody and give those guys time to develop."
Even Lannan said last week that Chico deserved to be in the rotation
"Chico was the workhorse last year," Lannan said. "Whoever they pick deserves it. They are all great pitchers. I don't even look at numbers. He went out there and had a good year. Last year, he was [almost] in the same boat as I was. He never pitched above Double-A. Given that, I thought he threw pretty well. He deserves to be up there."
Orr went 13-for-36 (.389), but he knew going into Spring Training that he didn't have a chance to make the roster.
"Pete Orr had a very good Spring Training, but it's a numbers deal," Acta said. "We like Willie Harris and what he brings to the table. He did a very good job for us in Spring Training."
Hanrahan, who is out of options, was arguably the biggest surprise in camp. He appeared to be a long shot to make the team, but Acta decided to put him in the bullpen, and he flourished in the role. Hanrahan didn't give up a run in 12 innings and struck out 14 batters.
His best game came against the Braves on March 11, when he fanned eight batters over three innings.
Schroder, who had a great season out of the bullpen last year, was a victim of the numbers game.
"Our last two moves on the pitching staff are going to be unfortunate because they should both be on the team," general manager Jim Bowden said, before announcing that Lannan and Schroder were demoted. "But they will be here in a short time. Within a couple of weeks probably. That part is difficult. It doesn't make you feel good. It's not that they don't understand, because they do. It's still unfair."
Boone, Harris, Mackowiak all proved this spring that they could be valuable backups. Boone can play the entire infield, while Harris can play seven positions. Harris and Mackowiak most likely will split time as the fourth outfielder.
Meanwhile, the Nationals will take six extra players to Washington, D.C., to participate in the exhibition game against the Orioles on Saturday. Langerhans, Orr, Schroder, Garrett Mock, Wil Nieves and Mike O'Conner will be part of the group before going back to the Minors after the game.
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.