VIERA, Fla. -- Before driving in the game-winning run in a 7-6 victory over the Cardinals on Sunday, infielder Zach Walters felt that he wasn't doing anything right every time manager Davey Johnson was watching him.

"I've been calling him 'The Warden,' because every where I turn, I feel I'm taking the wrong step. He is right there with his hawkeyes," Walters said.

As it turns out, Johnson is impressed with Walters. In fact, Johnson compared Walters to Ian Desmond.

"He has a lot of talent. He is a country boy. Strong like Desmond. He hasn't quite figured out who he is. He has a big upside," Johnson said.

Johnson would like Walters to stand more upright at the plate.

"He has been working out of a spread stance. I like to see him a little taller and use his strength and drive the ball," Johnson said. "He is very young. He has a really good upside."

Entering Monday's action, Walters is 4-for-17 [.235] with one RBI.

Asked how he is doing in camp, Walters said, "Overall, the biggest thing I'm trying to do is just work hard, blend in and kind of be a wallflower and not stick out too much. I don't need [Jayson] Werth, [Adam] LaRoche and those older guys barking at my neck. I'll work hard, see what I can do and then progress."

Ramos to get back behind plate on Tuesday

VIERA, Fla. -- Nationals catcher Wilson Ramos did something on Saturday that he wasn't able to do since last May. He slid seven times on the team's half field without any problems. Sliding was the last step for Ramos before he was able to play in a game.

"I felt pretty good," Ramos said. "I didn't have any pain. I wasn't sore. I'm no longer scared. I was happy. I was excited about that [Saturday]. But today is another day. I would have to do the same thing like yesterday. We'll see how it feels today."

Since Ramos passed the test when it comes to sliding, manager Davey Johnson put Ramos in Sunday's game against the Cardinals as a pinch-hitter for Ryan Zimmerman in the seventh inning. Ramos admitted he was nervous when he stepped into the batter's box. He grounded out to third base, but didn't have any problems running the bases.

"I just tried to put the ball in play and see how my knee felt," Ramos said. "I was running to first base, I felt good."

Said Johnson, "When he chopped that ball to third, he was running real hard to first, I said, 'Wil, don't run so hard.'"

In the ninth inning, Ramos doubled over James Ramsey's head in center field and left the game as Sandy Leon replaced him as a pinch-runner. Leon scored what proved the winning run in a 7-6, walk-off victory.

"I was waiting for something over the plate. … I felt much better at the plate. It was exciting," Ramos said.

Johnson also announced that Ramos would start against the Astros on Tuesday and play three innings behind the plate.

"I'm very excited to be able to play now," Ramos said. "I was waiting for that step. I'm crazy to play again. It's has been a long time. I missed a lot of games. I miss putting on my gear. Now, I'm able to play. I'm waiting for the moment."

Ramos missed most of last season because of a devastating right knee injury last May against the Reds. Johnson was impressed that Ramos came into camp in great shape after two major surgeries in June and July.

"He is in great shape. He has been taking extra work," Johnson said. "He has been throwing a lot. He has been blocking a lot. He has done everything every other guy in camp has done and I've seen him do it."

Ramos is expected to start the season as the backup catcher behind Kurt Suzuki.

Detwiler solid in final start before Classic

VIERA, Fla. -- Before heading off to the World Baseball Classic, Nationals left-hander Ross Detwiler pitched his last game for the Nationals and was solid in a 7-6 victory over the Cardinals. He pitched two innings, allowed a run on four hits with four strikeouts.

In the first inning, Detwiler allowed consecutive singles to Shane Robinson and Adron Chambers before striking out the side to end the threat.

The Cardinals scored their run off Detwiler in the second inning. With runners on first and second and nobody out, Justin Christian hit into a double play, but Tony Cruz scored on the play and tied the score at 1-1.

"I thought Det threw the ball really good. It was very tough out there -- windy, getting a feel for the ball," manager Davey Johnson said. "We were going to have him throw over 50 pitches and we managed to do that in two."

Detwiler is scheduled to pitch for Team USA on March 9.

Bray among four assigned to Minor League camp

VIERA, Fla. -- After their 7-6 victory over the Cardinals, the Nationals re-assigned pitchers Bill Bray, Brandon Mann, Will Ohman and Tanner Roark to Minor League camp. The Nationals currently have 50 players in their big league camp.

Manager Davey Johnson acknowledged the Nationals had too many pitchers in camp and ran out of innings for the pitchers who were sent to Minor League camp.

Of the four players, Bray most needs to fix his pitching mechanics. Johnson feels Bray can get it done in a less-stressful environment. Bray does not have an opt-out clause in his contract. Johnson didn't rule out Bray making the Opening Day roster if one of the relief pitchers goes down with an injury.

"We still like him a lot, like his makeup, like everything about him, but we would like him to get him back to the form when he was here," Johnson said. "I like the way he competes. I know [pitching coach Steve] McCatty is a little uncomfortable with his mechanics."

Bray acknowledged that he still needs to work on his mechanics. He needs to fix his arm slot.

"I think anybody who has seen me pitch before knows that it's not quite where it needs to be," Bray said. "The velocity is ticking up a little bit for me. My arm strength, my leg and back feels good. All the pieces are there. I just have to put it together."

Ohman didn't play in his first spring game until Sunday because of hamstring issues. Against the Cardinals, Ohman pitched one shutout inning, but walked two batters. Roark and Mann were hit hard, allowing a 11 runs in 5 1/3 innings.

Garcia still feeling pain in forearm

VIERA, Fla. -- Right-hander Christian Garcia said he still feels pain in his right forearm and will give it a rest for another week. He has not participated in baseball activities since mid-February.

While he is being shut down, Garcia is doing ultrasound and heating the forearm.

"There is nothing you can do. It's more rest than anything," Garcia said. "We are taking it day by day. I want to feel zero pain and then go from there."

When Garcia is ready to pitch, manager Davey Johnson indicated he would still like to see Garcia as a starter.

Worth noting

• Infielder Micah Owings has missed eight straight games because of a sore left wrist, but he took light swings in the batting cage on Sunday. There is no timetable as to when he will get into a game. According to Johnson, Owings recently had a cortisone shot in the wrist.

• Outfielder Eury Perez practiced with the Nationals on Sunday and then was expected to join Team Dominican Republic for the World Baseball Classic on Monday.