Walker said Wednesday was the first full day he experienced without any headaches since the collision, which, to his knowledge, was the first concussion he ever suffered.
"I may have had one in football back in [high school], but I've never blacked out before," Walker joked. "So that was a first."
Walker flew with the team from Oakland to Chicago before returning to Pittsburgh on Monday morning for evaluations. He said he's been examined by both team doctors and a neurologist, with all tests coming back negative.
Manager John Russell cautioned that the Pirates don't want to rush their second baseman back too soon, but remained optimistic of the timetable for Walker's return.
"Looking good. He's feeling pretty good, really not too many symptoms," Russell said. "If everything goes well today, we'll get him out for batting practice tomorrow and like a full workout before the game. If everything goes well there, then hopefully we can get him back in the game on Saturday, barring any setbacks."