WASHINGTON -- Nationals general manager Mike Rizzo acknowledged after Tuesday's 6-3 victory over the Braves that he scouted catcher Bryce Harper this past weekend in Las Vegas. The news was first reported by the Washington Post.

Rizzo said he was impressed with what he saw from the left-handed-hitting Harper, who plays for the College of Southern Nevada. The Nationals have the first overall pick in the 2010 First-Year Player Draft and Harper is one of several candidates who could be selected by the team.

"He played great," Rizzo said. "He has great energy, great tools and he is one of the five or six guys we are talking about taking with the first pick. He has great bat speed and great leverage power. He is already comfortable with the wooden bat."

Rizzo saw Harper catch and play right field. Rizzo said Harper is above average at both positions.

"He plays both of them extremely well," Rizzo said. "He has great talent behind the plate and great talent in the outfield."

Lannan to miss next start with elbow pain

WASHINGTON -- Nationals left-hander John Lannan is going to miss his next start this weekend against the Marlins because of left elbow discomfort. There is no talk of putting him on the disabled list. He will rest for five days in hopes that the pain will go away.

He started feeling discomfort in his elbow against the Rockies on April 21, when pitched six innings and gave up four runs on 11 hits. He picked up a no-decision in a 6-4 victory.

After the game, Lannan told the trainers about his problem and had an MRI. It revealed swelling in his flexor tendon, but no structural damage. Lannan was told he could still pitch, but he didn't have quality starts in his next two outings, allowing nine runs in 11 innings.

Lannan said he felt discomfort in the elbow while throwing his two-seam fastball and changeup, the two pitches he relies on the most. He said he knew something was wrong with the elbow in his last start against the Marlins.

"In my last start, I knew something was wrong," Lannan said. "I didn't have normal stuff. I didn't have the life that I usually have to get ground balls. I said something, so now I take the next step.

"Of course, it's frustrating. I've never been injured before. Hopefully, it gets better and this program works out. I'll skip my next start and be back for the next one."

The Nationals have not announced who will replace Lannan in his next start. Reliever Miguel Batista could get the start for Washington, which also could call up another arm for the bullpen. Reliever Drew Storen is not in the mix. Right-hander Joel Peralta and left-hander Doug Slaten, both from Triple-A Syracuse, are candidates.

Then again, the Nationals could call up a starter. Right-hander J.D. Martin of Syracuse and left-hander Matt Chico, who is pitching for Double-A Harrisburg, are candidates. Both have experience in the Major Leagues.

Marquis to begin throwing off mound

WASHINGTON -- Right-hander Jason Marquis, on the 15-day disabled list because of bone chips in his right elbow, said he will throw off the mound Wednesday after playing catch on flat ground the previous few days.

Marquis said he took enough time off for the inflammation to go away and his range of motion to come back.

Marquis is expected to be out of action from four to six weeks.

"It's a team decision," Marquis said. "I'm not going to put pressure on the team to let me come back early. I take pride in what I do. I finally feel healthy."

Robinson returns to Nationals Park

WASHINGTON -- Baseball Hall of Famer and former Nationals manager Frank Robinson was in Nationals Park on Tuesday afternoon to talk to the team about diversity in the Major and Minor Leagues and in the front office.

Robinson, who now works for Commissioner Bud Selig, said he doesn't have any ill feelings towards the Nationals, who relieved him of his duties as manager in 2006. He went so far as to say that if the team were to honor him, he would be open to attend the ceremony.

Robinson was the Nationals' first manager after they moved from Montreal to Washington, D.C., after the 2004 season. Under Robinson, the Nationals went 81-81 in 2005.

"I'm one to forget and forgive over time," Robinson said. "It takes a little while to get it out of my system, because that's the way I am. I think if I've been done wrong or something, it stings a while. All of that is gone. I have no animosity toward the Washington Nationals. If they would like to honor me, it would certainly be an honor and a privilege."

Robinson said he continues to follow the Nationals. He said they have a winning record because the pitching and defense has been good.

"They are playing very well," Robinson said. "They are in most ballgames now because they are not giving up a lot of runs. I think they can win. I don't know if they can win the division. They are causing a lot of problems [for opponents] right now, because pitching and defense is the game, and they are doing those things very well."