"Marion Barber is getting better," Bears coach Lovie Smith said. "He won't play this week."
The Bears held out Barber from Friday's session. But the running back hasn't worked out with the team since suffering the calf injury in the first half of the club's matchup on Aug. 27 against the Tennessee Titans.
Barber carried 20 times for 94 yards in the first two preseason games -- including a 45-yard effort in the exhibition opener against the Bills -- and sustained the calf injury on a 1-yard run in the first quarter against the Titans.
According to offensive coordinator Mike Martz, the team will miss Barber's skills as "a violent runner."
"He's a guy who can certainly jump cut and do all those things," Martz said. "But he'll take a defender on, too, and break tackles. He's kind of a complete back in that way."
With Barber out of the lineup, the team will call upon Kahlil Bell, who averaged 4.5 yards per carry over the preseason.
"Great opportunity [for Bell], you have to be ready," Smith said. "Kahlil has been in [this] position before. He's a pro. He's had a good camp. There's a reason why he's on our football team right now, and if you're a backup, this is the time that you want. If your number is called, the team expects us to have a running back in that position that can get the job done."
Meanwhile, Corey Wootton's knee injury probably won't be healed in time for him to face Atlanta, but the defensive end is expected to begin practicing without restrictions starting early next week.
Wootton and receiver Sam Hurd are both officially questionable on the Bears injury report.
"It's always tough to be out, because you're sitting around and you want to be locked in doing stuff," Wootton said. "Next week is the plan, to start resuming practice, and hopefully we'll go from there.'
"The training staff did a tremendous job. They've been getting me in there doing rehab once or twice a day depending on what we had going on. So I'm confident in being able to come back next week."
The second-year player from Northwestern underwent surgery to repair meniscus damage in his right knee he suffered while covering the opening kickoff of the Bears first preseason game against Buffalo.
"Nick Reed came in and we didn't know an awful lot about him, but he is a player who has earned a spot on our roster based on what he did in training camp each day, daily," Smith said. "And of course, based on what he did in the (preseason games), finishing up against Cleveland. If Nick Reed is the guy that's up, I feel very comfortable with him, as we would with Mario Addison too.
"Corey will eventually be out there and hopefully Sunday he'll be able to. But if not, those other guys will do a great job."
Michael C. Wright and Jeff Dickerson cover the Bears for ESPNChicago.com and ESPN 1000.