The only concern I have here is Shanahan has played fast and loose with the injury report before - i.e. Tatum Bell being listed as probable and not playing in two games. So I'd suggest keeping a close eye on the inactives and having a backup plan ready just in case something goofy happens here. I'd suggest picking up Brandon Marshall if you can. Cutler seems to like throwing to him and he could step into Walker's role and do well against the Bengals. But if he practices all week and remains probable it's hard to sit him if he's a guy you normally start. The matchup is good and he's obviously talented. Then it comes down to Cutler doing his part.
Excellent post. Regardless of Walker starting, the big question will be how long he can go, too. Discretion is the better part of valor here given all the negativity involved in this situation. Consider the following:
1) Walker is badly hurt
2) No receptions since the injury
3) In three games with Cutler at QB, he's seen a decline in his FF PPG average
Virtually no upside to Walker this week, but a ton of downside. Its statisitically impossible to start him this week and get an FF win.