Cameron, 39, decided to retire this past Wednesday, but general manager Mike Rizzo tried to talk him out of it. Rizzo wanted to give Cameron a few days to think it over, but Cameron never changed his mind.
Cameron said he wants to spend more time with his family and felt he didn't have the drive to get into baseball shape. Rizzo was not available for comment.
"It's been weighing on me for about two weeks," Cameron said via telephone. "I had been working out, but the actual drive wasn't there like it was over the years. It was the first time I ever had those kind of reservations.
"I almost felt I was letting people down. I decided not to play, so it has been hard. I've had so many people depend on me. The one thing I said, 'When I leave [the game], I gave every single ounce that I could give -- through the good and the bad.' It was a different feeling that came over me [to retire]. I still love the competition. I have to find something to keep me challenged."
If Cameron had played this season, he could have been in a platoon situation with Rick Ankiel in center field. With Cameron out of the picture, the Nationals could have Jason Michaels replace Cameron.
Then again, the Nats could choose to start the year with Jayson Werth in center field and Bryce Harper in right. Manager Davey Johnson has said he is going to give Harper every chance to make the team out of Spring Training.
Last season, Cameron played for the Red Sox and Marlins and hit a combined .203 with nine home runs and 27 RBIs. He is perhaps best remembered for being traded from the Reds to the Mariners as part of the deal that sent Ken Griffey Jr. to Cincinnati after the 1999 season.
While Griffey spent a lot of time on the disabled list, Cameron was an All-Star and a three-time Gold Glove Award winner. His best season was 2001, when he hit .267 with 25 home runs and 110 RBIs.
Cameron played for eight teams during his 17-year career, including the White Sox, Mets, Padres and Brewers. He had a career .249 batting average with 278 home runs and 968 RBIs, and was one of 15 players in big league history to hit four home runs in one game.
"I'm happy with what I've done in the game," Cameron said. "I do know that a lot of other people are really happy for me. My family is really excited about me being home."
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.