LAKE BUENA VISTA, Fla.-- Taking a conservative approach, Nationals manager Davey Johnson said that first baseman Adam LaRoche may not start against the Cardinals on Wednesday.

Johnson wants to see how well LaRoche is holding up before putting him in a game. Johnson didn't rule out giving LaRoche a couple of at-bats as a DH later in the game, but Johnson would prefer if LaRoche played with the regular position players, who are expected to get Wednesday off. LaRoche has yet to play because of a weak left shoulder and sore left ankle.

"I think he will be champing at the bit for tomorrow, but I'm not going to play him tomorrow. Hopefully, he'll be ready to go Thursday," Johnson said. "I would like to see him go through workouts, then go. It's a long spring. We have time. I'm not worried about getting enough playing time. I'm more concerned about him being all right."

Johnson to teach trio about playing second

LAKE BUENA VISTA, Fla. -- Nationals manager Davey Johnson said he plans to teach infielders Zach Walters, Danny Espinosa and Anthony Rendon about how to play second base the right way. The lesson will take place later this week at the Minor League field behind Space Coast Stadium.

The idea started when Walters said he wanted to pick Johnson's brain on how to play second base. Johnson said he is still concerned about the way Espinosa leaves himself vulnerable while turning the double play.

"Espi has a college degree at second right now, but he doesn't have his doctorate yet," Johnson said. "And he doesn't have the masters over there yet, either. So we are going to have a little session when we get back home."

Johnson said he learned how to play second base from former Yankees great Bobby Richardson and Hall of Fame second baseman Bill Mazeroski.

"They were both friends of mine when I came up, and I picked their brains," Johnson said. "Maz turned the double play better than any human being alive. His footwork was unbelievable. Neither one of them ever got taken out of second, and neither did I, because I had the tutelage."

Morse scratched late with right lat strain

LAKE BUENA VISTA, Fla. -- Nationals left fielder Michael Morse was a late scratch on Tuesday because of right lat (back) strain. He is listed as day to day. Bryce Harper, who was slated to enter the game late, started in right.

Morse said he started feeling pain in his back the last couple of days. He is having difficulty throwing the baseball.

"My back felt kind of tight. The other day, I was DHing and I didn't have to do any kind of throwing, so I took the day off that day and yesterday [I wasn't playing]," Morse said. "Today, just warming up, it felt kind of tight. There is no reason to push it this early. It's something that I need a little break, a little rest. Probably a little overworked or something."

Manager Davey Johnson said that he plans to be conservative with Morse, so look for Morse to be out of action for a few days.

In other news, Johnson said that outfielder Jayson Werth suffered forearm tightness in Tuesday's game against the Braves, but the injury is not considered serious. Werth had an opposite-field home run in the second inning and went 1-for-2 in the contest.

DeRosa happy to find power stroke

LAKE BUENA VISTA, Fla. -- Entering Spring Training, Nationals infielder/outfielder Mark DeRosa said his biggest concern was hitting for power. Several surgeries to his left wrist zapped his power the last 2 1/2 years.

His concerns appear to be over. In the fourth inning in a 5-2 victory over the Braves on Tuesday, DeRosa swung at a pitch from reliever Johnny Venters and hit a solo home run over the left-field wall to give Washington a 4-0 lead. It was DeRosa's first home run since April 5, 2010.

According to manager Davey Johnson, after he came into the dugout and was greeted by teammates, DeRosa joked, "Whoa, whoa, I'm back."

"It felt great," a happy DeRosa said. "I've been staying short [in my swing]. I've been through so much these last 2 1/2 years. I'm just happy to be healthy, and I feel good. These guys have welcomed me with open arms and it has been just an easy, smooth transition coming into this clubhouse with these guys.

"Offensively, I've felt good the whole offseason. I started swinging after the new year. I was finally hitting without pain. I try not to think about it. Every day I wake up, it's a good day. I've been going to the field and am able to work on my craft and get ready for the season, as opposed to limiting myself, being in pain. I'm staying out of the training room. That has been the nicest thing."

Gio happy with first outing for new club

LAKE BUENA VISTA, Fla. -- Left-hander Gio Gonzalez made his Nationals debut on Tuesday and was solid in a 5-2 victory over the Braves.

Although he was a bit anxious, Gonzalez was able to calm down after talking to pitching coach Steve McCatty, who told him to just relax and pound the strike zone.

"It's great to have him in your corner when he is talking to you like that," Gonzalez said about McCatty. "You know he keeps it loose and you have fun out there."

Gonzalez was definitely having fun. He pitched three shutout innings, allowing one hit, striking out two batters and walking one. His fastball was clocked as high as 95 mph, although he felt the radar gun was juiced.

"I felt great, this is all thanks to our defense. They gave me some confidence and thanks to [catcher] Wilson Ramos, he did a great job behind the plate, calling a great game," Gonzalez said. "All the credit goes to them. ... There is stuff I want to work on. I still want to get some breaking balls over for strikes, and the changeup. Again, this is a first outing for me. There's more to go."

Johnson not worried by Desmond's slow start

LAKE BUENA VISTA, Fla. -- Entering Wednesday's action, Nationals shortstop Ian Desmond has three errors in three games.

Manager Davey Johnson believes that Desmond is carrying his at-bats on to the field. Desmond is 0-for-9 with three strikeouts.

"He is so driven. He tries to overachieve," Johnson said about Desmond. "He sometimes takes his at-bats to the field. You concentrate on getting your timing and stroke. I thought he swung the bat better today. I'm not that concerned with it right now."

Harper learns lesson on basepaths

LAKE BUENA VISTA, Fla. -- Nationals right fielder Bryce Harper was overly aggressive on the bases during the second inning of 5-2 victory over the Braves.

After he singled with one out, Harper advanced to second on a slow roller by Wilson Ramos, who was thrown out at first. Harper then tried to go to third on the play, before he realized that shortstop Andrelton Simmons was covering third base.

Harper then stopped between second and third and tried to go back to second base, but was thrown out in a rundown. After talking to third-base coach Bo Porter, Harper said he should have been more conservative on the bases. Had the two teams played National League rules, Harper did not want the pitcher to lead off the inning. Instead, outfielder Brett Carroll was hitting ninth.

"I just put my head down and decided to go," Harper said. "I didn't recognize that the shortstop was at third base, pretty much. Bo made me more aware of that. If it's a real game, we have the pitcher coming up that next inning. You don't want that. I was not aware of my surroundings and seeing the guys and things like that."

Entering Wednesday's action against the Cardinals, Harper is 5-for-11 with a walk this spring.

"I'm a little bit patient. I've seen a lot of pitches and things like that," Harper said.

Nats shortstop Walters nursing sore right hand

LAKE BUENA VISTA, Fla. -- Nationals shortstop Zach Walters, who made a great defensive play against the Mets on Monday, has an injured right hand suffered on a check swing. Walters has had a problem for about a week, but didn't complain until Monday.

"He said something to the doctors, but I don't think it's real serious with him," manager Davey Johnson said.

Walters is currently playing in the Nationals' accelerated development program. He joined the Nationals organization in a trade that sent right-hander Jason Marquis to the D-backs last summer.