"Baby steps," Campbell said. "It's not going out there and swinging for the fences the first day. I'm just trying to get some strength."
Coach Joel Quenneville ruled Campbell out for the first couple games of their playoff series against the Nashville Predators, which opens on Friday, but would not rule out playing him later in the series.
Doctors declared Campbell out for eight weeks after getting hit into the boards by Capitals forward Alex Ovechkin, who was suspended for two games after delivering the blow.
"We didn't anticipate him playing for the first part of this series, but we'll see how he progresses as we get some practice days in him," Quenneville said. "How he's skating, how he's handling contact.
"It was good to see him out there. It looked like he fit right in there and handled it pretty well. Earlier on when he was injured, we didn't think it was on the radar. We'll see."
Campbell ran all the normal drills on Wednesday but did not take part in any special teams work or take a position with another regular defenseman. He took some slapshots but not with full force.
Campbell says he's been doing everything possible to get back as fast as he can.
"There's an Airdyne bike there in the back," Campbell said. "There's taking every legal pill in the book that will allow me to heal faster. [There's] eating things that are not a whole lot of fun to eat. These are precious days right now."
One thing Campbell can do now is sleep.
"It's not the easiest thing," Campbell explained. "Sleeping while sitting up. Anybody want to go home and try that, you're welcome to. If they get more sleep than 45 minutes, they can come let me know."
Campbell says he will see the doctors by the end of the week, and at that point he might have a better idea of when he can play.
"It's an important time of the year," Campbell said. "No one wants to sit around now.
Campbell had seven goals and 31 assists in 68 games before going down with the injury.
Jesse Rogers covers the Blackhawks for ESPNChicago.com.