Edge guys are not just DEs in this case but it extends not only to OLBs (f.e. KVN, M.Flowers) but also to some secondary guys to help secure the line. It worked decently vs BUF and NYJ even w/o KVN for most part. You need some speed there. Roberts is the MLB choice in big formations, KVN likely in dime and possibly M.Flowers in 7-DB sets (that probably won't be used as much as vs NYJ).
I like Harris and Id certainly have him over Grissom f.e. and maybe use him over Roberts in certain situations in this particular game but it just might be too hard for him to find a place on the active roster w/o ST value.
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Here's what Reiss projects for inactives:
Burkhead,
Gillislee,
Croston,
Jean-Francois,
Harris,
Grissom,
Britt.
That would be my call as well if Branch is in good enough shape.