Trumbo has been out since April 21 with a stress fracture in his left foot, and Gibson said he's still working toward full mobility.
"I think everything [is still troublesome for Trumbo]," Gibson said. "Just the sheer volume of what he does. Personally, I haven't seen him run … I don't think he's been in the outfield like running around and catching balls. I don't think he's there yet."
However, Gibson said Trumbo is still aiming for a July return.
"He's coming along on schedule," Gibson said.
Adam Lichtenstein is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.