Tillman was the Bears' rookie of the year, starting 13 games and establishing himself as a future star and the team's best cover corner. He faced some of the NFL's best wideouts and was never overmatched. In fact he made one of the best defensive plays of the year when he saved a Bears victory by taking the ball away from Randy Moss in the end zone.
Azumah came back from an early-season demotion to nickel back and played the best corner of his five-year career. He tied Tillman for the team lead with four interceptions. He also led the NFL in kickoff-return average, which earned him his first trip to the Pro Bowl.
McQuarters would be an ideal nickel were it not for his inflated salary, which counts $4 million against the cap. He's a top-notch punt returner, too, but he'll probably have to take a pay cut to stick around.
Brown had a disappointing season. He missed too many tackles and made too few big plays and big hits.
Gray is a much bigger hitter than Green and much more effective vs. the run. But, because of a stubborn coaching staff, he couldn't get on the field until Green suffered a groin injury. Gray quickly became the most intimidating hitter in a secondary that was missing that ingredient. Green looks like a good dime back, but he's not a quality starter.
McMillon and Williams are solid extra DBs in passing situations, and McMillon is an outstanding special-teams player.
Overall the team is happy with the secondary and it's unlikely that a major move will be made to add talent to the group. The only real debate is whether or not McQuarters will take a pay cut. If that doesn't happen then there could a shift in the secondary.
Green would move to the nickel back, thus opening the door for Gray to be the starting strong safety.
The biggest hole McQuarters departure would leave is replacing him on punt returns, but Bobby Wade is an option.
The Insiders contributed to this report.