Both Olsen and MacDougal are coming off injuries. Olsen missed most of the season because of a small tear in his left labrum, going 2-4 with a 6.03 ERA in 11 games, while MacDougal, who ended the season as the Nationals' closer, saved 20 games with a 3.60 ERA but needed offseason surgery on his right hip.
General manager Mike Rizzo said the Nationals were not willing to tender contracts to MacDougal and Olsen because they weren't sure if they were going to be 100 percent healthy. Rizzo also did not rule out both players returning to the team.
"These are very difficult decisions because these are guys that we really, really like," Rizzo said. "They were great teammates this past season. These are business decisions. We have to do what is best for the franchise."
It was believed that Nieves would be non-tendered after the Nationals signed catcher Ivan Rodriguez to a two-year $6 million, but they decided to keep Nieves because they feel he has been a valuable player -- offensively and defensively -- off the bench the last two years and can be insurance in case Jesus Flores is not ready for Spring Training.
Flores had surgery on his right shoulder and right elbow, and the team announced as recently as Friday that he would be ready for Spring Training.
"I can only go by what the medical people tell me. They say Jesus should be 100 percent ready to participate in Spring Training," Rizzo said on Friday. "We take them at their word, but we all know that shoulders are very difficult to predict."
As for Willingham, he is coming off a productive season. He started the year on the bench, but became a regular in June and hit .260 with 24 home runs and 61 RBIs. Willingham has been mentioned in trade rumors recently. Teams such as the Mets and Braves have interest in acquiring his services.
Bergmann showed improvement after the All-Star break, going 2-3 with a 3.38 ERA as a reliever. Rizzo and manager Jim Riggleman often talked about wanting Bergmann back for the 2010 season.
"In my heart of hearts, I've been in this organization a long time. I love people that I play with and play for. I would like to stick around for a long time," Bergmann said on Wednesday.
Bruney, who was acquired from the Yankees this past week, will compete for the closer's role during Spring Training.
Burnett was a quality reliever for the Nationals, who acquired him and center fielder Nyjer Morgan in a trade that sent outfielder Lastings Milledge and right-hander Joel Hanrahan to the Pirates in late June. In 33 games for Washington, Burnett went 1-1 with a 3.20 ERA.
Olsen, who made $2.8 million in 2009, said he was not surprised that he was non-tendered. He said the shoulder is 100 percent and hopes to return to the Nationals, a team he feels is going in the right direction under Rizzo and Riggleman.
"It's not an unexpected move by the organization. We have to see how this plays out," Olsen said. "I don't have any plans to go anywhere else since I got traded over there. I think Washington is a great place to play. I would love to go back there."
"With Scotty having the arm surgery at the end of the season, we are not sure where he is physically," Rizzo said. "We couldn't take a chance offering him a contract and going to arbitration with him.
"Mike was the same type of situation. He did a nice job for us. He is a guy we really counted on this year. He performed well for us. With the little bit of inconsistency toward the end of the season and then the hip surgery, it was too big of a risk for us."
MacDougal expressed disappointment that he was non-tendered, in part, because of his hip injury. He said that the hip is 100 percent and he will start working out at the end of this month.
"I'm disappointed," MacDougal said. "I enjoyed playing there. I thought I did a good job, so yeah, it's a little disappointing. What can you do? I'm a free agent and go from there."
MacDougal's agent, Rex Gary, said that Rizzo never told him that the hip played a role in MacDougal getting non-tendered.
"Michael was at the doctor and had a great report and everything is fantastic," Gary said. "The hip was never brought up as an issue and it really isn't an issue."
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.