Baker said he's hoping Heisey and Raburn will return soon. Heisey strained his groin Sunday and Raburn was placed on the disabled list Wednesday with a left trapezius strain.
Because his left toe injury hasn't healed quickly, Werth has stopped running. He's still able to perform most baseball activities, such as hitting. Baker also said outfielder Michael Taylor is "progressing well" from his right oblique strain, but he doesn't want to rush him back.
With only three healthy outfielders on the roster, backup first baseman Adam Lind has started in left field the past three games, and he has been solid.
The Nationals traded for two veteran relievers about two weeks ago, but they're still waiting for more bullpen help.
After throwing a simulation game Wednesday, reliever Shawn Kelley will go on a rehab assignment soon after landing on the the DL June 18 with a right trapezius strain. Right-hander Koda Glover, who's been on the DL since June 11 with back and shoulder issues, threw up to 90 feet Thursday in Florida.
On top of these injuries, Stephen Strasburg is missing his start Saturday, and leadoff hitter Trea Turner is still on the DL with a fractured wrist.
Still, the Nationals have a 13-game lead over the Braves in the National League East, so Baker wants his players healthy for the postseason.
"You've got to get them back soon enough to be sharp and effective in the postseason," Baker said. "Because [if they're] back ... just to be back and not sharp, it's going to be detrimental to us. But we'd love to have them back, as they're my starters. I'm hoping that we kind of get them back one at a time in chronological order to help us."
Kyle Melnick is a reporter for MLB.com based in Washington. This story was not subject to the approval of Major League Baseball or its clubs.