Right-handers Craig Stammen and Chien-Ming Wang are the likely candidates to get a spot start on Sunday, according to manager Davey Johnson.
Johnson does not want any of his regular starting rotation to have to come back on three days rest and prefers a right-hander against the Brewers' power-hitting lineup.
He has not made his selection yet, wanting to wait to see how his bullpen is taxed here in the Dodgers series.
"It depends on these next couple of games," Johnson said. "It could be a guy in our bullpen. I probably won't bring anybody back on short (rest). Wang, Stammen, it will probably be a right-hander against Milwaukee, not a left-hander.
"It depends on how much I use the guys out of the 'pen, how these games go. If I work somebody pretty heavy tomorrow, they would have two days off and still start. It is like side work."
It looks more and more like Johnson may have more confidence in giving Stammen his first start since 2010. He made 24 starts for Triple-A Syracuse last season.
Wang has yet to pitch with the Nationals this month after returning from his rehab assignment at Double-A Harrisburg. Johnson is a little worried that Wang has not been built up since that time to take on the task of five or six innings.
"That is the concern I have there," Johnson said. "He has been throwing some 'pens. He would probably be in the mix that day."
What was also interesting was Johnson's reaction to Orioles top prospect Dylan Bundy being called up from their Florida instructional league camp to the majors. He said the Nationals have a couple of prospects on their Florida instructional league team that could be helpful for them if the need arises.
"We got a few guys down in instructs, too, in the wings," Johnson said.
He did not mention any names, but a quick look at the roster reveals that right-hander Robert Gilliam, who pitched for Double-A Harrisburg, and left-hander Robbie Ray, who started 21 games for high Single-A Potomac, might be long-shot possibilities.
Turning to today's Game 1 starter, Johnson was asked if he has seen anything different with Jordan Zimmermann as the season progresses. Could Zimmermann be slowing down due to shoulder soreness that bothered him earlier this season?
"A lot of times when he has got too strong, he kind of would jump at the hitter. That is part of pitching up here, your past experiences (help you to) know how to handle them," Johnson said. "A lot of the guys in this rotation are still very young and learning about pitching at this level with an extra days rest. It is a learning experience and he is a smart guy."
Zimmermann had 21 starts of six or more innings to begin the season. Since then, he has pitched six or more innings in just one of his last eight starts. But Johnson sees no cause for concern.
"I look at his stuff is still very good," Johnson said. "At times, through a long course of the year, you can go through a little tired arm, sometimes you can go through little things against certain ballclubs that made adjustments against you. There are all kinds of reasons. But I like the way the ball is coming out of his hands and that is all I care about. The ball is coming out of his hand real good."