"We are going to turn the page. We are going to get younger the last two months of the season and we are going to continue to develop young players," general manager Jim Bowden said. "We want players that are going to hustle, play the game hard and play the game right. We just feel we need to give younger players an opportunity. We are going to do that."
Lopez, who was acquired from the Reds on July 13, 2006, was a disappointment with the Nationals. After hitting .281 during the second half of '06, Lopez couldn't get his bat going and was shaky on defense. He hit .245 last year and was hitting .234 at the time of his release.
"It's disappointing," Bowden said. "I traded for him twice. I'm a fan of his talent and his ability. It didn't happen here in Washington. I'm sorry for that and I'm sure he is sorry for that. I love Felipe. We just couldn't get the talent out on the field."
There were times when teammates and the front office felt that Lopez didn't play hard, but Lopez denied it. He said he was often frustrated and it showed on the field.
"For people who play this game, it's hard when you struggle," Lopez said. "You roll over a ball and you cuss yourself out down the first-base line. It might seem like I'm not hustling to other people. It's just frustration."
Lo Duca, 36, was having the worst season of his career, hitting .230 with 12 RBIs. His season got off on the wrong foot when he injured his left knee while exercising in a gym last January. Lo Duca started the season on time, but he ended up going on the DL twice with right-hand injuries.
By the time he came back in mid-June, Lo Duca lost his starting job to Jesus Flores. Lo Duca then saw playing time in left field and at first base. At one point, he was the everyday first baseman, but he lost his job on Thursday, when Casto was inserted into the starting lineup.
Lo Duca took the news very well and understands that the Nationals are going into a youth movement. He plans to go home to New York and try to find a job with another team. Lo Duca is aware that the Marlins need a starting catcher.
"When Jim and Manny called me in there, I apologized. I feel bad. I'm a better player than I played," Lo Duca said. "It has been an unfortunate year. I had the knee surgery and just when I started to feel healthy, I broke my hand.
"Kory needs to play. He is the future of this organization as well as Jesus. They need to play. Giving me my release is sort of a class act by them. To give me a chance to hook up with another team is a big-time class act."
Estrada was designated for assignment last week. He had 10 days to be either traded or claimed off waivers.
Estrada, 32, batted .170 with four RBIs in 23 games with Washington. He missed 69 games this season because of a right elbow injury.
The Nationals get even younger with Bonifacio and Dukes on the roster. Bonifacio will now become the everyday second baseman, while Dukes will reclaim his position in left field.
Bonifacio, who will wear No. 6, was acquired from the Diamondbacks for reliever Jon Rauch last week. Bonifacio then went to Columbus and went on a tear. Bonifacio hit .452 (14-for-31) with three RBIs, four walks, four stolen bases and nine runs scored with Columbus.
Dukes is coming back almost four weeks after he hurt his right knee on July 5 against the Reds. He was supposed to be out until late August or early September.
Dukes, 24, went 5-for-15 (.333) with two doubles, one RBI, two walks and a .412 on-base percentage in four rehab starts with Columbus.
With Dukes returning, it means Willie Harris will be back on the bench. Harris proved to be a valuable everyday player. He hit .291 with four home runs and 15 RBIs during the month of July.