I don't know if they have announced how long Forte is out, but he is someone you might consider. If he's out for several weeks, he may have more value to you than anyone else in your league because you Michael Bush, who is a solid RB2 (at worst) as long as Forte is injured, and when Forte comes back you can just swap the two of them in your starting lineup. The longer he is projected to be out, the lower you should be able to get him for.
As a McFadden owner, I'm a little nervous right now. Yes, he produced decently in week 1, but it was on flukish reception numbers. The Oakland offense just looks awful right now. You might be able to get him for a little cheap, but his owners would likely not want to get rid of their 1st/2nd round pick so soon for a low enough price.
Unfortunately you have the RB with the lowest stock in the NFL right now on your roster. You can't really afford to get rid of him because you won't get anywhere near the price you paid for him on draft day. CJ might have a bad season, but it's hard to imagine it won't get better.