LAKE FOREST, Ill. -- Chicago Bears wideout Johnny Knox plans to eventually make a full recovery from a fractured vertebra that required surgery, but the fourth-year receiver could not rule out the possibility of being forced to miss the entire 2012 season as he continues to rehab daily at the team's practice facility.

Knox addressed reporters on Wednesday after the Bears' second OTA of the offseason at Halas Hall.

"It could happen, but I'm staying optimistic," Knox said. "My main focus is in that weight room. That's all I'm focusing on. I'm not in a rush [to return]; this is my spine, the core of my body that I'm dealing with. This is not my knee or my ankle or my shoulder ... I'm taking my time on this."

The injury to Knox occurred Dec. 18 against the Seattle Seahawks when he fumbled after making a 17-yard catch on a slant route. As Knox was scrambling on the ground to recover the loose ball, he was hit by ex-Seahawks defender Anthony Hargrove and essentially bent backwards. Knox was carted off the field and underwent surgery the next day to stabilize a vertebra in his spinal column.

Five months later, Knox still has not watched a replay of the hit.

"No, I actually haven't; I probably don't want to see it until I retire," Knox said.

The injury was so serious that after surgery Knox, listed by the Bears at 6 feet, 185 pounds, had to wear a brace for 2½ months, which caused him to drop 30 pounds. Knox said he has gained back 10 of those pounds.

"It was tough at first [wearing the brace], but I got used to it; it was all for a good reason," Knox said. "My doctors and the training staff stayed on me hard and wanted to keep me in it because it helped me get right. I just got to keep rehabbing and I'll get back out there as soon as I can. My main focus right now is in that weight room, because if I don't get stronger in that weight room, I won't be able to come out here and practice with the team.

"It's hard to say [when I'll be back]. I want to get back out there at the beginning of the season but who knows. We're going to see how that turns out."

No timetable has been given regarding when Knox will be medically cleared to resume practicing. Knox was one of eight players to sit out Wednesday's workout, a list that also included Brian Urlacher, Matt Forte, Patrick Mannelly, Gabe Carimi, Kelvin Hayden, Kellen Davis and D.J. Moore. The club is expected to open training camp in late July with the first regular-season game scheduled for Sept. 9 against the Indianapolis Colts.

"I really don't know [when I'll be able to practice]," Knox said. "They haven't given me a timetable on that right now.

I've been out here jogging a little bit just trying to get some muscle memory back, but as far as routes, I'm just working on the little things right now. That, and staying in my playbook."