"If he's not going to be here it's going to hurt tremendously," said Falcons quarterback Michael Vick. "Ray is a big asset to our team and he provides a lot of leadership."
Bears starting quarterback Jim Miller said the team will test Buchanan's replacement Juran Bolden, who is listed on the injury list with a hamstring problem.
"It's going to be interesting to see if they do the same sort of coverages. With Buchanan and Ashley Ambrose they feel they can matchup on anybody. Now we'll see how that effects things. Again, we're going to have to make adjustments by what they do cause they might not do all the same things of what they would do if Buchanan was in there."
Chicago's passing attack is coming off a stellar showing against Minnesota throwing for 297 yards. The Bears should be able to attack the weakened Falcons secondary.
Atlanta head coach Dan Reeves said Buchanan's loss will hurt the team on several levels.
"I think anytime you a starter, particularly at the corner position that always hurts," Reeves said. "You lose a starting defensive corner you have somebody else that steps up you hope will be a quality player.
"It has a rippling effect on your team because now you lose a special teams player and you have to add somebody to our squad."