Reed has been on the PUP (physically unable to perform) list after undergoing offseason hip surgery to repair damage suffered last season.
Reed can return after the sixth week of the regular season, which is Sunday against the Patriots at Gillette Stadium.
“I think he’ll be ready to go,” Harbaugh said. “Obviously, you never know until the guy gets out there and starting practicing. But based on the way he’s moving around now, I don’t see any way he won’t be ready to go.”