According to Brad Biggs:
"As for center, the Bears have confidence Edwin Williams can do the job if Kreutz, an unrestricted free agent, doesn’t return, which remains a possibility. There even have been discussions about moving Chris Williams to center, which would be a stunning admission for a team that drafted Williams 14th overall in 2008 to be the left tackle of the future.
On the other hand, the 6-6, 315-pound Williams would provide the added bulk Tice is looking for. Because his strength is his intelligence, he could make the line calls required of a center. The lack of aggressiveness he has displayed at guard and tackle would be less of a concern at center, where he would be required to make fewer one-on-one blocks."