Obviously losing Jackson for an extended time and Nelson for the season is a big loss for the team. I was thinking about the way this will effect the offense, and there are at least a few things that thought of that may ultimately help the team. Other than the extended role for Spiller it's tough to view the Jackson injury in a positive light. I'm praying that Choice serves as nothing more than a change of pace back because I have never been very impressed with what he has done on the field and I think Gailey has far too much faith in him.
However I think Nelsons injury will force the Bills to put some potentially more effective packages on the field. Imagine the Bills putting out a typical 3 WR set with 1 TE and 1 RB. Typically this package would consist of Johnson, Jones, Nelson, Chandler, and Jackson/Spiller. The way I see it the Bills will now use one of two different sets of personal to create this same look.
The first option would be to slide Jones into the slot and put TJ Graham on the outside. While Jones isn't as reliable in the short passing attack as Nelson he is a more explosive option. Graham, while raw, provides a big play threat and could help stretch the defense vertically. This package will provide a lot more big play potential and force the defense to compensate to take away the big play, potentially opening things up for Chandler, Johnson, and Spiller underneath. I would expect to see this package on passing downs.
The Bills probably wont want to use Graham on all the 3 WR sets. The second option would be to slide Chandler into the slot and bring in Lee Smith to play TE. This set will be an advantage on first and second downs as well as on 3rd and 5 or less. Chandler is a similar type player to Nelson in the slot as both are long targets that have reliable hands. I don't think there is a huge drop-off between the two players in this role, although Chandler does present much less of a down field threat. The advantage that could result from this formation is the addition of Lee Smith and his run blocking ability. This formation could allow for better running lanes and give Spiller a better shot of breaking more long runs. While Smith won't be a big threat in the passing game he is still reliable enough that the defense will have to account for him underneath.
edit: bigtuna44 suggested below that Dickerson could also be used as a H-back in place of Smith. This is certainly another viable option worth exploring. It could provide the same benefits while increasing the versatility of the personal grouping. This would be worth exploring to see if Dickerson is up to the task and Gailey has already installed a solid framework for using an H-back in our offense.
Essentially, these new personal groupings could provide more big play potential and better run blocking ability. I hope that Gailey uses on of these two groupings at least 75% of the time we give a 3 WR look. I would be hesitant to use Spiller at WR too often even when Choice is on the field, as I would prefer to keep him as fresh as possible for his RB reps. I also expect B. Smith will also see increased reps at WR in place of Graham on some looks, but I'm hoping Graham is effective enough to minimize the need to put other WR's in his place. I'm also holding onto hope that with Nelson gone Gailey will see a role open up for the reliable Namen Rosevelt and resign him when we eventually release one of the back-up QB's (likely Thigpen) and slide Smith back to the 3rd QB spot on the roster.