Bears' secondary shuffle continues

CHICAGO -- Lovie Smith has once again changed up his secondary as the Chicago Bears prepare to face the St. Louis Rams Sunday at Soldier Field.

According to a league source, rookie Al Afalava is being switched to free safety on Sunday, while Kevin Payne is being inserted into the starting lineup at strong safety.

Payne's ability to make plays in the box should help the Bears contain dangerous Rams running back Steven Jackson.

As the Chicago Sun-Times first reported, Danieal Manning is being moved back exclusively to nickel. The shift should allow Manning to focus on covering St. Louis rookie receiver Brandon Gibson in the slot. The Rams opened up with a three-receiver set last Sunday versus Seattle.

Another player to keep an eye on is cornerback Charles Tillman, who despite being listed as having full participation in Thursday's practice, is not a lock to face the Rams because of the concussion he suffered last Sunday in Minnesota. If Tillman is out, he is expected to be replaced by Corey Graham in the starting lineup.