The rest of the positions were up for grabs.
"I'm just trying to play the guy who's going to give me the best chance any given day to win," Acta said.
Lately, the guy at second base has been Willie Harris.
Harris, who hit eighth and played second base again on Monday, has appeared in 10 straight games for the Nationals and has been playing a lot of second because of the various injuries on Washington's roster. The extended play has been a huge boost for the 30-year-old's offensive numbers.
Harris started the season 2-for-24 while playing sporadically in the outfield. But over his last seven appearances entering Monday, he had gone 8-for-20 -- a .400 batting average -- and Washington has won three out of its last four.
In the fourth inning of Monday's game, he plated Ronnie Belliard with an RBI single off Florida starter Ryan Tucker.
"When the season ends, there's no way I'll be hitting .200," Harris said about his current .198 batting average. "[The Nationals] know that, I know that. It's just a matter of getting out there, getting consistent at-bats. You know, you get 10 straight at-bats and try to get three hits, you're a great hitter.
"That's what I try to do. I try to break my at-bats down and just get hits."
But Harris' biggest asset may not be his production. It's his demeanor.
"Energy and desire [are what Harris brings]," Acta said. "I don't worry about him being out there running balls out, running through a wall or doing anything possible to win a ballgame. You root for people like that, and he's been a spark for us.
"Even when he was struggling most of the first half, he never put his head down, and always played hard. I guess everybody roots for people like that."
But Harris says that kind of attitude on the field is just second nature to him.
"I bring fire," he said. "I'm going to play the game hard, I'm going to run out weak grounders, I'm going to do all those little things, because that's just who I am.
"I try to spark my lineup, but it's just me. I've been like that ever since I can remember."
Alden Gonzalez is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.