According to the Sun Times, Graham has "quietly" taken Vasher's role as the starting cornerback. This is not due to injury, but performance. Remember back earlier in the year when Graham started and Vasher was relegated to back-up duty? Looks like even before Vasher's illness, there's been some questions about his performance.
If Graham is indeed the starter for the rest of the season, the Bears have a few options to deal with this situation. They could a) keep him and his high salary in a reserve role or b) trade him to a team with a need for DB.
I really can't see the Bears keeping Vasher if he is a reserve the rest of the year. I don't know how you could justify keeping that much money in a player that would sit a majority of the time. I'm somewhat intrigued at the trade prospect. We could easily trade for a WR (Boldin, for example), OL, or whatever else we wanted. Let's say we tried trading for Boldin. The Cardinals, if they had any sense, wouldn't trade Vasher for Boldin straight up. We would have to give up a draft pick most likely, but it would be a much lower pick than if we wanted to pick up Boldin and not trade anyone away.
EDITED: What I meant to say (and I didn't make clear) was that this trade scenario would take place in the offseason. If Vasher does not reclaim the starting role before the end of the season, what would you want to happen?