There is nothing Zimmerman can do to expedite the process, though he hopes to be out for less than a month.
"Right now, we are letting it rest," Zimmerman said. "Hopefully at some point this week, we'll start doing some stuff and have a better idea [when I'll be back]. It's starting to feel better, which is a good sign. Hopefully, it will continue to feel better in the next few days. We really don't know much until I start doing stuff."
Zimmerman was hitting .209 with five home runs, and his 34 RBIs ranked second on the team entering Tuesday.
In other news, Washington reliever Aaron Barrett threw on flat ground before Tuesday's game, according to manager Matt Williams. Barrett has been on the disabled list since June 12 with a right biceps strain.
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.