Yeah, this really isn't that big of a deal. We're talking about a guy who even in a 'best case scenario' might've seen 10 minutes per game. I think what so many people are forgetting is that Marquis and Eddie are going to eat up pretty much all the backup 1-3 minutes in games that matter. So who the other backup win happens to be really doesn't matter right now. The team will be just fine with Scal, TA, or J.R. filling this role.
Also, this could work out for the best for the C's. If this season is a wash for Walker, the C's will be able to pick him up for cheap next summer. Then if he does really emerge, they'll have his Bird Rights.