VIERA, Fla. -- Nationals outfielders Michael Morse and Rick Ankiel and first baseman Adam LaRoche can't play in Grapefruit League games because of injuries, but they can get at-bats on the Minor League field, manager Davey Johnson said.

LaRoche continues to have a left foot problem and feels pain when he runs the bases. LaRoche hurt the foot while doing a baserunning drill last month.

Morse recently had an MRI exam, and it revealed that he still has a strained right lat muscle. Morse, who has played three exhibition games, can swing a bat, but he still can't throw a baseball. Ankiel continues to have left hamstring issues and has not played since March 9 against the Marlins.

Like with outfielder Bryce Harper earlier this week, LaRoche, Morse and Ankiel must work out in front of Johnson in order to play in a Grapefruit League game.

"For this time of year, I'm cautious," Johnson said. "My conversation with the trainer today was, 'Ankiel, Morse and LaRoche: Treatment here [Space Coast Stadium], they can hit over there [Minor League Field] under your supervision.' I'm going to be on the cautious side. We got a ways to go. Those guys don't have to prove anything to me. My main concern is getting them ready. It depends on how quickly they recover."

Zimmermann, Johnson pleased with outing

VIERA, Fla. -- Nationals right-hander Jordan Zimmermann made his third start of the spring on Saturday afternoon and was solid in a 1-1 tie against the Marlins. He pitched four shutout innings, allowing five hits and striking out three batters. He threw 78 pitches, 54 for strikes.

"It's getting better and better every day," Zimmermann said. "I felt better today than I did the last start. ... I had really good control with all of my pitches. I felt pretty good today."

Manager Davey Johnson felt Zimmermann's outing was great because the Marlins were fouling off a lot of his pitches.

"Zim was great," Johnson said. "I thought he threw the ball exceptionally well. He was really strong at the end there, too. He was a little wild, but it was hard and great stuff."

Nats endure late baserunning mistake

VIERA, Fla. -- In the ninth inning of a game that ended in a 1-1 tie on Saturday afternoon, the Nationals had a chance to score the winning run against Marlins reliever Sandy Rosario.

With runners on first and third, no outs and the infield in, Jhonatan Solano hit a sharp grounder to second baseman Donavon Solano, who was able to throw out the Nationals catcher at first base. Brett Carroll was then caught in a rundown between first and second and was tagged out to complete the double play.

Nationals manager Davey Johnson felt Jason Michaels, who was on third, should have ran on contact and headed home, while Carroll should have made it to second base. Johnson seemed more critical of how third-base coach Bo Porter and first-base coach Trent Jewett handled the play.

"There was some difference of opinion between the first-base coach and the third-base coach," Johnson said. "We were protecting against the line drive. Don't worry about [line drives]. In that case, you get another guy [Carroll] in scoring position. That's what you do.

"On the ground ball, you still have the guy in scoring position and then he goes. It was a baserunning mistake. We have been pretty good [running the bases], but that wasn't pretty."

Nats to carry seven relievers, two long men

VIERA, Fla. -- Nationals manager Davey Johnson plans to carry seven relievers on his 25-man roster, with two of them expected to be long relievers. Those long relievers most likely will be Ross Detwiler and Tom Gorzelanny, who will get spot starts during the season.

With Chien-Ming Wang hurting because of a strained left hamstring, John Lannan is expected to be the fifth starter.

"Of those seven [relievers], I do like two starters in the 'pen in case one of my starters had any kind of problem warming up or whatever," Johnson said. "That's why you need two, because you might have to let a long guy go two or three innings the day before. You certainly wouldn't want to put that guy back out there to risk injury or put him in a tough situation."

Catcher Maldonado impresses Nationals

VIERA, Fla. -- Manager Davey Johnson said that outside of Wilson Ramos and Jesus Flores, Carlos Maldonado has been the most impressive of the Nationals catchers this spring.

Entering Saturday's action against the Marlins, Maldonado was 2-for-6 (.333) with a home run and three RBIs. Johnson also likes the way Maldonado can handle a pitching staff.

"It's very comforting from a managing standpoint to see him handle a pitching staff," Johnson said. "He showed he can drive in some key runs. Very veteran-like player and a quality catcher. ... I didn't see him play last year or the year before. It's just great being around him and seeing him perform and how he handles things."

Maldonado most likely will stay with the Major League team until the end of Spring Training, and then start the season with Triple-A Syracuse as a backup. Johnson said Jhonatan Solano most likely will be the No. 1 catcher for Syracuse.