ATLANTA -- The Nationals purchased the contract of catcher Wilson Ramos from Triple-A Syracuse on Wednesday and placed catcher Wil Nieves on the temporary leave list. Nieves is going Washington to be with his wife, who gave birth to a girl, Maria Isabel, on Wednesday night. Maria came in at a healthy 7.06 pounds and 20.5 inches.

Ramos will be Washington's backup catcher until Nieves returns to the team on Friday against the Phillies. Manager Jim Riggleman didn't rule out Ramos starting against the Braves on Thursday.

Ramos will be sent back to Syracuse once Nieves returns, but will get a September callup.

Ramos was acquired from the Twins for reliever Matt Capps on July 29. Since the trade, Ramos has been productive, hitting .317 with two home runs and six RBIs for the Chiefs.

The Nationals are hoping to have Ramos, 23, for a long time, as he is a highly regarded prospect. He made his Major League debut this year for Minnesota and was 8-for-27 (.296) with an RBI.

Before the trade to Washington, Ramos was playing for Triple-A Rochester, hitting .241 with five home runs and 30 RBIs.

"My first time in the big leagues, I was very excited," Ramos said. "In my first game, I went 4-for-5. The second one, I went 3-for-4. When Minnesota sent me to Triple-A, I was a little bit down because I know I can play in the big leagues. When I was traded, I was excited because I know I have more of an opportunity. I'm going to play hard here and see what happens."

While he is with the team, Ramos hopes to learn a lot from starting catcher Ivan Rodriguez, his boyhood hero.

"Right now, there is an opportunity to learn from him and talk a lot to him," Ramos said.

The Nationals were in need of catching depth because Jesus Flores has missed the entire season with a right shoulder injury. There isn't a timetable on when he will return to the big leagues. Flores has dealt with the injury since May 2009 -- when he was hit by a foul tip off the bat of D-backs outfielder Chris Young.

Washington's other top catching prospect, Derek Norris, has also missed a lot of time because of injuries. He still needs to work on his game behind the plate.

Willingham set to go on DL

ATLANTA -- The Nationals plan to place outfielder Josh Willingham on the 15-day disabled list on Thursday because of a meniscus problem in his left knee.

The team is waiting until Thursday to make the move because center fielder Nyjer Morgan is eligible to come off the disabled list that day. Morgan rejoined the team Wednesday and took batting practice.

Willingham, who is affectionately known as "Hammer," has had knee problems since April. But it grew worse recently.

After Sunday's game, in which he collected two hits against the D-backs, Willingham's knee started to bother him. It grew worse when he flew back to Alabama to be with his family on Monday.

The pain didn't subside once he arrived in Atlanta on Tuesday. Willingham will need surgery to fix the problem. It's just matter of when.

If Willingham misses the rest of the season, look for the Nationals to use Roger Bernadina in left, Morgan in center and Mike Morse in right.

Olsen not happy about being pulled

ATLANTA -- Left-hander Scott Olsen acknowledged on Wednesday that he was not happy about being lifted in the sixth inning of Tuesday's 10-2 loss to the Braves.

Olsen was pitching a perfect game until the fourth inning, when Omar Infante led off with a single.

Suddenly, Olsen couldn't get anyone out in the bottom of the sixth inning. Diory Hernandez, pinch-hitting for Braves starter Mike Minor, hit a home run to make it a one-run game. After Infante tripled and Jason Heyward walked, manager Jim Riggleman decided to take Olsen out of the game in favor of Joel Peralta. Olsen, who was upset about his departure, was seen screaming into his glove and throwing his glove in the dugout.

"I was frustrated," Olsen said. "It doesn't matter what I think. I wouldn't want to make that decision."