Some of my thoughts:
WR
Darius Slayton (drops are the biggest issue with him)
DeMarcus Robinson (re-sign despite the suspension)
Allen Lazard (Jets are likely to cut him; intriguing player due to his size and blocking ability)
TE
Mark Andrews (might be available for trade)
Kyle Pitts (might be available for trade)
Michael Mayer (might be available for trade)
Kylen Granson (undersized move TE who suffered due to poor QB play in Indy)
OL
Alaric Jackson (re-sign or franchise and re-sign)
Josh Jones (solid swing OT)
Daniel Brunskill (solid utility OL)
DL
Greg Gaines (NT depth)
Bobby Brown III (try to retain)
TJ Slaton (NT to replace Brown)
EDGE
Michael Hoecht (try to retain)
Azeez Ojulari (worth considering on a cheap prove it deal; has had injury issues, but he can get after the QB)
Darrell Taylor (if he's available for a cheap prove it deal, worth considering due to his pass rush potential)
LB
Nick Bolton (would solve many of our run defense problems; physical Mike who has great instincts; only 24)
Dre Greenlaw (Has had injury issues and is older than Bolton, but he is a very good ILB when healthy)
Zack Baun (Bit of a risk as a one-year wonder, but I loved him as a prospect; boom/bust signing)
Robert Spillane (veteran who defenders the run at a high level)
CB
Charvarius Ward (very good CB, but he's older [turning 29])
Ahkello Witherspoon (solid player for us; try to retain)
Carlton Davis (good CB, but not sure he's a scheme fit unless we want to run more press; durability is also an issue)
Eric Stokes (has shown flashes, but has been up and down in Green Bay)
Asante Samuel Jr. (good fit for the scheme we've been running, but I'm hoping for somebody bigger and stronger)
FWIW, I'm not very high on Byron Murphy (inconsistent in coverage) or D.J. Reed (too small). I think we need more size and run defense at CB.