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Chris Johnson's strong spring has made him a leading candidate to be the Houston Astros' opening day third baseman.

Johnson hit his third home run of the spring and Bud Norris and Lucas Harrell pitched three hitless innings and the Astros beat the Washington Nationals 5-1 on Friday.

The Nationals are 0-9-1 in their past 10 spring games.

But the big news for the 27-year-old Johnson came earlier in the day when the Astros optioned Jimmy Paredes, his chief competitor for the third base job, to Triple-A Oklahoma City and moved him to second base.

Manager Brad Mills wasn't ready to write Johnson into the opening day lineup yet. Brett Wallace, last year's opening day starter at first base, appears to be the only remaining competition, and he hasn't played third base in the major leagues.

"There's no doubt C.J. has had an outstanding spring and he's got the upper hand simply because of how he has played," Mills said. "But let's see how things play out. C.J. has been extremely professional and we want him to continue to do that, but we don't want to discount the other guys either."

If Johnson starts at third base on April 6 against Colorado, he could be the only Astros player to start at the same position on opening day in 2011 and 2012.

Carlos Lee, who started the 2011 opener in left field, has played first base exclusively this spring. Brett Myers, last year's opening day starter, is now Houston's closer.

Johnson lost the job to Paredes last year, but he came to camp knowing it is a new era for the Astros, who have new ownership, a new general manager and a lot of new players.

"There are so many people seeing me for the first time," he said, "and I want to make that good first impression. That's the way I'm going about it."

He is hitting .353 this spring and is the only Houston player with three home runs.

Paredes hit .286 in 46 games as a 22-year-old third baseman last year.

He has not had a good spring, however, and the Astros decided he was playing out of position.

"When he was with the Yankees he started as a shortstop and got moved to second base," general manager Jeff Luhnow said.

"Really I was trying to figure out from the time I got here why he was at third base because he really does seem to have all the tools and skill set to play the middle infield."

Jayson Werth's single off Myers in the seventh inning was the first hit for the Nationals. Jason Michaels homered in the eighth.

Norris gave up one walk while striking out three before being lifted for a pinch hitter in the third inning.

"I know I have to get up to 85 or 90 (in two more starts)," he said, "but the biggest thing is to start the season healthy and not over-push yourself right now, just make sure you're ready on Day One."

Jordan Zimmermann gave up four runs and eight hits, including a home run to Brian Bixler, in five innings for the Nationals.

Manager Davey Johnson said Zimmermann will "more than likely" pitch Washington's third game, after Stephen Strasburg and Gio Gonzalez.

"Today was a good tuneup for Zim. I think one more and he's going to be ready," Johnson said, who is not concerned about his team's bad spring numbers.

"I've told them it's a long spring, and I want you ready for opening day. I think we've done that," he said.

NOTES: Center fielder Jordan Schafer, who injured his left hand Sunday, will probably be back in the Astros lineup by the end of the weekend, Mills said. ... Friday's six cuts left the Astros with 41 player, including 19 pitchers. ... The Nationals have 37 players.