Tillman could be out a while

Every team deals with some sort of bad news during the preseason, and the Bears' first dose came before their first practice of training camp.

Charles Tillman, their best cornerback, will miss a lot of the preseason after undergoing arthroscopic surgery to repair a disc in his back.

The Bears think Tillman will be fully recovered before the regular season kicks off Sept. 13, but the secondary will spend training camp and at least two or three of the exhibition games trying to cover for his absence.

Corey Graham, who started much of last season with Nathan Vasher injured, is a strong possibility. But Graham was shifted to safety during the offseason and the coaches might not want to move him back, at least not full-time.

Second-year pro Zack Bowman, who stood out during the offseason program, could be with the first team when practice gets going Friday afternoon. Graham certainly will get his share of repetitions no matter what.

The other guys who will move up the depth chart are rookie D.J. Moore, a fourth-round draft pick, and third-year pro Trumaine McBride.

The secondary already was an issue on defense with Craig Steltz, Graham and Josh Bullocks all as unproven options to take over at free safety. Vasher has something to prove after two injury-marred seasons, and strong safety Kevin Payne remains a developing -- but promising -- player.

Tillman was the surest thing in the defensive backfield even after missing most of the offseason program because of shoulder surgery. Now that he's undergone another surgery, you have to wonder whether he's getting past his prime from a physical standpoint.

If he's fine by Sept. 13, this injury could have a silver lining in that it gives Bowman and others more of a chance to develop. But if Tillman struggles to get back, the questions on defense will get harder to answer.

If you're wondering about external options at cornerback, there's predictably not a lot to choose from: Mike McKenzie, Brian Kelly, Fakhir Brown and Deltha O'Neal.