"He still feels it, unfortunately," manager Matt Williams said. "So it's light [work] in the cage -- fungo, tee work and a little bit of soft toss. He is trying to work through that part of it. He is day to day, still. That's the best way we could put it."
Zimmerman's injury came at a bad time. He had been Washington's hottest hitter, going 22-for-60 (.367) with seven home runs and 25 RBIs in his last 15 games. During Zimmerman's absence, Clint Robinson and Tyler Moore have platooned at first base.
• Reed Johnson, who has been out most of the season because of a foot injury and a broken rib, was working in the outfield without any problems on Wednesday. Williams said Johnson has to pass a number of tests before he is activated from the disabled list. Beginning with Thursday's series finale against the Orioles, the Nationals have 11 games left in the regular season.
"[Johnson] had good defensive work today, and he is hitting in the first group [during batting practice] today," Williams said. "He feels good about his rib. He'll progress. We'll see how it goes the next few days."
Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the Time. He also can be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.