"Once the doctor clears him, then he can start all his strengthening exercises," Williams said.
Williams said that Zimmerman is capable of lifting, running and catching balls, but still can't put any stress on the fractured thumb, which has been "immobilized." So Zimmerman will have work to do to get the thumb back to full strength.
"It's a question of pain tolerance," the Nationals manager said. "Continue to look at the X-rays and not go too fast. If we push him or he pushes himself too hard and he re-fractures it, that's eight weeks -- minimum."
Washington has also checked on Zimmerman's shoulder during the process, and if there's any silver lining for the Nats, it's that the inflammation that has perpetually bothered him is gone.
"We can certainly feel confident that the inflammation's out of there," Williams said.
David Wilson is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.