"Still working on trying to run and seeing if I can get that squared away," said Murphy, who spoke with reporters Wednesday for the first time since returning Monday from extended spring training.
"I see these guys competing so hard each night. To not be able to do that with them is frustrating," he said. "As far as running goes, I still have a little bit of a hitch in my giddy up. I am not running the way I would if I was 100 percent."
Meanwhile, third baseman Anthony Rendon will begin a rehab assignment Thursday at Class A Potomac.
Manager Dave Martinez said Rendon (left toe contusion) will play one or two games there.
Rendon hasn't played since fouling a ball off his foot against the Colorado Rockies on April 13.